From 541cbe1b04d5e804d2cabe879317cff9ae3f5cb4 Mon Sep 17 00:00:00 2001
From: Mohammad S Anwar <mohammad.anwar@yahoo.com>
Date: Tue, 7 Jun 2022 17:54:35 +0100
Subject: - Added guest contributions by Eric Cheung.

---
 challenge-168/eric-cheung/python/ch-1.py | 39 ++++++++++++++++++++++
 challenge-168/eric-cheung/python/ch-2.py | 57 ++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100755 challenge-168/eric-cheung/python/ch-1.py
 create mode 100755 challenge-168/eric-cheung/python/ch-2.py

(limited to 'challenge-168')

diff --git a/challenge-168/eric-cheung/python/ch-1.py b/challenge-168/eric-cheung/python/ch-1.py
new file mode 100755
index 0000000000..df5ae80e8e
--- /dev/null
+++ b/challenge-168/eric-cheung/python/ch-1.py
@@ -0,0 +1,39 @@
+
+## Remarks
+## https://en.wikipedia.org/wiki/Perrin_number
+
+import math
+
+def IsPrime(nInput):
+
+    for nDiv in range(2, int(math.sqrt(nInput)) + 1):
+        if nInput % nDiv == 0:
+            return False
+
+    return True
+
+arrPerrinPrime = []
+arrPerrinNum = []
+
+arrPerrinNum.append(3)
+arrPerrinNum.append(0)
+arrPerrinNum.append(2)
+
+arrPerrinPrime.append(2)
+arrPerrinPrime.append(3)
+
+while len(arrPerrinPrime) < 13:
+    nNuNum = arrPerrinNum[-2] + arrPerrinNum[-3]
+    arrPerrinNum.append(nNuNum)
+
+    if not IsPrime(nNuNum):
+        continue
+
+    nCount = arrPerrinPrime.count(nNuNum)
+
+    if nCount > 0:
+        continue
+
+    arrPerrinPrime.append(nNuNum)
+
+print (arrPerrinPrime)
diff --git a/challenge-168/eric-cheung/python/ch-2.py b/challenge-168/eric-cheung/python/ch-2.py
new file mode 100755
index 0000000000..4bcd6f1e3a
--- /dev/null
+++ b/challenge-168/eric-cheung/python/ch-2.py
@@ -0,0 +1,57 @@
+
+## Remarks
+## https://en.wikipedia.org/wiki/Home_prime
+
+import math
+
+def IsPrime(nInput):
+
+    for nDiv in range(2, int(math.sqrt(nInput)) + 1):
+        if nInput % nDiv == 0:
+            return False
+
+    return True
+
+
+def PrimeFact(nOrigInput):
+
+    nInput = nOrigInput
+    arrPrimeFact = []
+
+    for nDiv in range(2, nOrigInput):
+
+        while nInput % nDiv == 0 and nInput > 0:
+
+            nInput = nInput / nDiv
+            arrPrimeFact.append(nDiv)
+
+        if nInput == 0:
+            break
+
+    return arrPrimeFact
+
+
+def ConcatArray(arrInput):
+
+    strResult = ""
+
+    for arrElem in arrInput:
+        strResult = strResult + str(arrElem)
+
+    return int(strResult)
+
+
+## print (PrimeFact(511))
+## print (ConcatArray(PrimeFact(511)))
+## print (ConcatArray(PrimeFact(8)))
+
+
+nOrigInputNum = 10
+
+nInputNum = nOrigInputNum
+
+while not IsPrime(nInputNum):
+    nInputNum = ConcatArray(PrimeFact(nInputNum))
+
+print ("HP(" + str(nOrigInputNum) + ") = " + str(nInputNum))
+
-- 
cgit 


From ac32e51ae34212cd68b2cfdd8f72f54681006e29 Mon Sep 17 00:00:00 2001
From: Mohammad S Anwar <mohammad.anwar@yahoo.com>
Date: Tue, 7 Jun 2022 18:13:36 +0100
Subject: - Added solutions by Robert DiCicco.

---
 challenge-168/robert-dicicco/julia/ch-1.jl  | 37 +++++++++++++++++++++
 challenge-168/robert-dicicco/perl/ch-1.pl   | 47 ++++++++++++++++++++++++++
 challenge-168/robert-dicicco/perl/ch-2.pl   | 51 +++++++++++++++++++++++++++++
 challenge-168/robert-dicicco/raku/ch-1.raku | 41 +++++++++++++++++++++++
 challenge-168/robert-dicicco/raku/ch-2.raku | 51 +++++++++++++++++++++++++++++
 challenge-168/robert-dicicco/ruby/ch-1.rb   | 37 +++++++++++++++++++++
 6 files changed, 264 insertions(+)
 create mode 100644 challenge-168/robert-dicicco/julia/ch-1.jl
 create mode 100644 challenge-168/robert-dicicco/perl/ch-1.pl
 create mode 100644 challenge-168/robert-dicicco/perl/ch-2.pl
 create mode 100644 challenge-168/robert-dicicco/raku/ch-1.raku
 create mode 100644 challenge-168/robert-dicicco/raku/ch-2.raku
 create mode 100644 challenge-168/robert-dicicco/ruby/ch-1.rb

(limited to 'challenge-168')

diff --git a/challenge-168/robert-dicicco/julia/ch-1.jl b/challenge-168/robert-dicicco/julia/ch-1.jl
new file mode 100644
index 0000000000..45d1bbcd64
--- /dev/null
+++ b/challenge-168/robert-dicicco/julia/ch-1.jl
@@ -0,0 +1,37 @@
+#!julia.exe
+
+# AUTHOR: Robert DiCicco
+# DATE: 2022-06-06
+# Challenge 168 Perrin Primes ( Julia )
+
+using Primes
+
+perrin = [3,0,2]
+
+results = []
+
+PRIME_COUNT = 13
+
+i = 0
+
+while i <= PRIME_COUNT
+
+  slots = size(perrin,1)
+
+  calc_val = perrin[slots - 1] + perrin[slots - 2]  # since julia arrays are option base 1
+
+  push!(perrin,calc_val)
+
+  if isprime(calc_val)
+
+    push!(results,calc_val)
+
+    global i += 1
+
+  end
+
+end
+
+results = unique!(sort(results))
+
+println(results)
diff --git a/challenge-168/robert-dicicco/perl/ch-1.pl b/challenge-168/robert-dicicco/perl/ch-1.pl
new file mode 100644
index 0000000000..b72ac33280
--- /dev/null
+++ b/challenge-168/robert-dicicco/perl/ch-1.pl
@@ -0,0 +1,47 @@
+#!perl.exe
+
+# AUTHOR: Robert DiCicco
+# DATE: 2022-06-06
+# Challenge 168 Perrin Primes ( Perl )
+
+use strict;
+use warnings;
+use feature qw/say/;
+use ntheory qw/is_prime/;
+use List::MoreUtils qw(uniq);
+
+my @perrin = qw(3 0 2 );      # working array
+
+my @results = ();
+
+my $i = 0;
+
+my $PRIME_COUNT = 13;
+
+while($i <= $PRIME_COUNT) {
+
+  my $slots = scalar(@perrin);
+
+  my $calc_val = $perrin[$slots - 2] + $perrin[$slots - 3];
+
+  push(@perrin, $calc_val);
+
+  if (is_prime($calc_val)) {
+
+    push(@results, $calc_val);
+
+    $i++;
+
+  }
+
+}
+
+@results = sort { $a <=> $b } uniq(@results);
+
+foreach(@results) {
+
+  print("$_ ");
+
+}
+
+print("\n");
diff --git a/challenge-168/robert-dicicco/perl/ch-2.pl b/challenge-168/robert-dicicco/perl/ch-2.pl
new file mode 100644
index 0000000000..8ecf170a47
--- /dev/null
+++ b/challenge-168/robert-dicicco/perl/ch-2.pl
@@ -0,0 +1,51 @@
+#!perl.exe
+
+# AUTHOR: Robert DiCicco
+# DATE:   2022-06-06
+# Challenge 168 Home Prime ( Perl )
+
+use strict;
+use warnings;
+use ntheory qw/is_prime factor divisors/;
+
+my $hp = 8;
+my @results;
+
+sub homeprime {
+  my $hp = shift;
+
+  my @factors = factor($hp);
+
+  my $hp_new = join('',@factors);
+
+  return($hp_new);
+
+}
+
+my $flag = 1;
+
+push(@results, $hp);
+
+while ( $flag > 0) {
+
+  my $retval = homeprime($hp);
+
+  if ( is_prime($retval) ){
+
+    push(@results, $retval);
+
+    $flag = 0;
+
+  } else {
+
+    push(@results, $retval);
+
+    $hp = $retval;
+
+  }
+
+}
+
+  print ("@results ");
+
+  print("\n");
diff --git a/challenge-168/robert-dicicco/raku/ch-1.raku b/challenge-168/robert-dicicco/raku/ch-1.raku
new file mode 100644
index 0000000000..acfda4039c
--- /dev/null
+++ b/challenge-168/robert-dicicco/raku/ch-1.raku
@@ -0,0 +1,41 @@
+use v6;
+
+# AUTHOR: Robert DiCicco
+# DATE: 2022-06-06
+# Challenge 168 Perrin Primes ( Raku )
+
+my @perrin = (3,0,2);
+
+my @results = ();
+
+my $PRIME_COUNT = 13;
+
+my $i = 0;
+
+while $i <= $PRIME_COUNT  {
+
+  my $slots = @perrin.elems;
+
+  my $calc_val = @perrin[$slots - 2] + @perrin[$slots - 3];
+
+  @perrin.push: $calc_val;
+
+  if $calc_val.is-prime {
+
+    @results.push: $calc_val;
+
+    $i++;
+
+  }
+
+}
+
+@results = @results.sort.unique;
+
+for @results -> $val {
+
+  print "$val ";
+
+}
+
+say ' ';
diff --git a/challenge-168/robert-dicicco/raku/ch-2.raku b/challenge-168/robert-dicicco/raku/ch-2.raku
new file mode 100644
index 0000000000..1db7b563b2
--- /dev/null
+++ b/challenge-168/robert-dicicco/raku/ch-2.raku
@@ -0,0 +1,51 @@
+use v6;
+
+# AUTHOR: Robert DiCicco
+# DATE: 2022-06-06
+# Challenge 168 Home Primes ( Raku )
+
+use Prime::Factor;
+
+my @results;
+
+sub homeprime( $hp)  {
+
+  my @factors = prime-factors($hp);
+
+  return(@factors.join);
+
+}
+
+my $hp = 8;
+
+my $flag = 1;
+
+@results.push: $hp;
+
+while $flag > 0  {
+
+  my $retval = homeprime($hp);
+
+  if $retval.is-prime {
+
+    @results.push: $retval;
+
+    $flag = 0;
+
+  } else {
+
+    @results.push: $retval;
+
+    $hp = $retval;
+
+  }
+
+}
+
+for @results -> $val {
+
+  print "$val ";
+
+}
+
+say ' ';
diff --git a/challenge-168/robert-dicicco/ruby/ch-1.rb b/challenge-168/robert-dicicco/ruby/ch-1.rb
new file mode 100644
index 0000000000..0a050d6120
--- /dev/null
+++ b/challenge-168/robert-dicicco/ruby/ch-1.rb
@@ -0,0 +1,37 @@
+#!ruby.exe
+
+# AUTHOR: Robert DiCicco
+# DATE: 2022-06-06
+# Challenge 168 Perrin Primes ( Ruby )
+
+require 'prime'
+
+perrin = Array[3,0,2]
+
+PRIME_COUNT = 14
+
+results = Array.new()
+
+i = 0
+
+while i < PRIME_COUNT
+
+  slots = perrin.length()
+
+  calc_val = perrin[slots - 2] + perrin[slots - 3]
+
+  perrin.push(calc_val)
+
+  if Prime.prime?(calc_val)
+
+    results.push(calc_val)
+
+    i += 1
+
+  end
+
+end
+
+results = results.sort.uniq
+
+puts "#{results }"
-- 
cgit 


From fe5f85a0913b16129fd528a9f43472c3012bd2de Mon Sep 17 00:00:00 2001
From: Mohammad S Anwar <mohammad.anwar@yahoo.com>
Date: Tue, 7 Jun 2022 18:18:31 +0100
Subject: - Added guest contribution by Robert DiCicco.

---
 challenge-168/robert-dicicco/julia/ch-2.jl | 45 ++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 challenge-168/robert-dicicco/julia/ch-2.jl

(limited to 'challenge-168')

diff --git a/challenge-168/robert-dicicco/julia/ch-2.jl b/challenge-168/robert-dicicco/julia/ch-2.jl
new file mode 100644
index 0000000000..e486810da1
--- /dev/null
+++ b/challenge-168/robert-dicicco/julia/ch-2.jl
@@ -0,0 +1,45 @@
+#!julia.exe
+
+# AUTHOR: Robert DiCicco
+# DATE: 2022-06-07
+# Challenge 168 Home Primes ( Julia )
+
+using Primes
+
+results = []
+
+function homeprime( hp )
+
+  temp = []
+
+  s = " "
+
+  temp = factor(Array, hp)
+
+  for i in 1:length(temp)
+
+    s = s * repr(temp[i])
+
+  end
+
+  return(parse(Int64, s))
+
+end
+
+hp = 8
+
+flag = 1
+
+push!(results,hp)
+
+while flag > 0
+
+  retval = homeprime(hp)
+
+  push!(results,retval)
+
+  isprime(retval) ? (global flag = 0) : (global hp = retval)
+
+end
+
+println(results)
-- 
cgit 


From e1189741ce4605921a45e07944a2d2be784d6139 Mon Sep 17 00:00:00 2001
From: "E. Choroba" <choroba@matfyz.cz>
Date: Tue, 7 Jun 2022 21:30:33 +0200
Subject: Add solutions to 168: Perrin Prime & Home Prime by E. Choroba

---
 challenge-168/e-choroba/perl/ch-1.pl | 24 ++++++++++++++++++++++++
 challenge-168/e-choroba/perl/ch-2.pl | 17 +++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100755 challenge-168/e-choroba/perl/ch-1.pl
 create mode 100755 challenge-168/e-choroba/perl/ch-2.pl

(limited to 'challenge-168')

diff --git a/challenge-168/e-choroba/perl/ch-1.pl b/challenge-168/e-choroba/perl/ch-1.pl
new file mode 100755
index 0000000000..4f1355475d
--- /dev/null
+++ b/challenge-168/e-choroba/perl/ch-1.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+use Syntax::Construct qw{ // };
+
+use Math::Prime::Util qw{ is_prime };
+
+sub perrin_prime {
+    my ($length) = @_;
+    my @perrin_sliding = (3, 0, 2);
+    my @perrin_primes;
+    while (@perrin_primes < $length) {
+        push @perrin_sliding, shift(@perrin_sliding) + $perrin_sliding[0];
+        push @perrin_primes, $perrin_sliding[1]
+            if $perrin_sliding[1] > ($perrin_primes[-1] // 0)
+            && is_prime($perrin_sliding[1]);
+    }
+    return @perrin_primes
+}
+
+use Test::More tests => 1;
+
+is_deeply [perrin_prime(13)], [2, 3, 5, 7, 17, 29, 277, 367, 853, 14197,
+                               43721, 1442968193, 792606555396977];
diff --git a/challenge-168/e-choroba/perl/ch-2.pl b/challenge-168/e-choroba/perl/ch-2.pl
new file mode 100755
index 0000000000..f53c124f35
--- /dev/null
+++ b/challenge-168/e-choroba/perl/ch-2.pl
@@ -0,0 +1,17 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+
+use Math::Prime::Util qw{ factor is_prime };
+
+sub home_prime {
+    my ($i) = @_;
+    my $concat = join "", sort { $a <=> $b } factor($i);
+
+    return $concat if is_prime($concat);
+
+    return home_prime($concat)
+}
+
+use Test::More tests => 1;
+is home_prime(10), 773;
-- 
cgit 


From 0dda125086968453130299deda173151b91da413 Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Wed, 8 Jun 2022 20:03:50 +0800
Subject: improved solution to ch-1 and added solution to ch-2

---
 challenge-168/steve-g-lynn/julia/ch-1.jl | 29 +++++++++++++++
 challenge-168/steve-g-lynn/perl/ch-1.pl  | 48 +++----------------------
 challenge-168/steve-g-lynn/perl/ch-2.pl  | 37 +++++++++++++++++++
 challenge-168/steve-g-lynn/raku/ch-1.p6  | 37 +++----------------
 challenge-168/steve-g-lynn/raku/ch-2.p6  | 61 ++++++++++++++++++++++++++++++++
 5 files changed, 136 insertions(+), 76 deletions(-)
 create mode 100755 challenge-168/steve-g-lynn/julia/ch-1.jl
 create mode 100755 challenge-168/steve-g-lynn/perl/ch-2.pl
 create mode 100755 challenge-168/steve-g-lynn/raku/ch-2.p6

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/julia/ch-1.jl b/challenge-168/steve-g-lynn/julia/ch-1.jl
new file mode 100755
index 0000000000..e58d43e005
--- /dev/null
+++ b/challenge-168/steve-g-lynn/julia/ch-1.jl
@@ -0,0 +1,29 @@
+#!/usr/bin/julia
+#-- slower than perl or raku for this task because of slow startup
+
+using Primes
+
+function perrin(n::Int64)
+	return ( ([0 1 0; 0 0 1; 1 1 0]^n)*[3;0;2] )[1];
+end
+
+savedprimes=Array{Int64}(undef,13)
+savedprimes[1]=2; savedprimes[2]=3;savedprimes[3]=5;savedprimes[4]=7
+ctr=3;
+
+for n in (6:1000)
+	perrinval=perrin(n)
+	if (isprime(perrinval) && (ctr <=13))
+		savedprimes[ctr]=perrinval
+		global ctr=ctr+1
+	end
+end
+
+print("(")
+for n in (1:13)
+	print(savedprimes[n])
+	print(" ")
+end
+print(")\n")
+
+
diff --git a/challenge-168/steve-g-lynn/perl/ch-1.pl b/challenge-168/steve-g-lynn/perl/ch-1.pl
index a8729418aa..35818da7f9 100755
--- a/challenge-168/steve-g-lynn/perl/ch-1.pl
+++ b/challenge-168/steve-g-lynn/perl/ch-1.pl
@@ -3,8 +3,11 @@
 use Math::Prime::XS qw(is_prime);
 
 local %saveprimes=();
-for (0..150) {
-	local $chk=&perrin($_);
+local @perrin=(3,0,2);
+for (1..150) {
+	local $chk=$perrin[0];
+	push @perrin, $perrin[0]+$perrin[1];
+	shift @perrin;
 	(is_prime($chk)) && ($saveprimes{$chk}=1);
 	@saveprimes==26 && last;
 }
@@ -15,45 +18,4 @@ foreach (sort{$a<=>$b} keys %saveprimes){
 }
 print ")\n";
 
-#-- subs
 
-
-sub perrin {
-	local ($n)=@_;
-	
-	if ($n==0) { return 3 }
-	else { return &postmult_302(&matpow($n)) }
-}
-
-#-- subs for fast computation of perrin number using matrix formula
-#-- see wikipedia https://en.wikipedia.org/wiki/Perrin_number
-
-#-- [0 1 0; 0 0 1; 1 1 0]^n (only need 1st row)
-sub matpow {
-	local ($n)=@_;
-	
-	if ($n==1) { return (0,1,0) }
-	else {return &postmult_010_001_110(&matpow($n-1))}
-}
-
-
-# 3x3 matrix * [0 1 0; 0 0 1; 1 1 0] (retain 1st row of product)
-sub postmult_010_001_110 {
-	# [a11 a12 a13; a21 a22 a23; a31 a32 a33]*[0 1 0; 0 0 1; 1 1 0]
-	local ($a11,$a12,$a13)=@_; #just need 1st row
-	
-	local $b11=$a13;
-	local $b12=$a11+$a13;
-	local $b13=$a12;
-
-	return ($b11,$b12,$b13) #-- return just 1st row
-}
-
-# 3x3 matrix * [3;0;2] retain 1st element of product
-sub postmult_302 {
-	local ($a11,$a12,$a13)=@_; #-- just need 1st row
-	# [a11 a12 a13; a21 a22 a23; a31 a32 a33]*[3;0;2]
-	#
-	return $a11*3+$a13*2; #-- 1st element
-
-}
diff --git a/challenge-168/steve-g-lynn/perl/ch-2.pl b/challenge-168/steve-g-lynn/perl/ch-2.pl
new file mode 100755
index 0000000000..d1f6f0aced
--- /dev/null
+++ b/challenge-168/steve-g-lynn/perl/ch-2.pl
@@ -0,0 +1,37 @@
+#!/usr/bin/perl
+
+use Math::Prime::XS qw(is_prime sieve_primes);
+
+
+print &home_prime(16),"\n";
+#-- should be 31636373 [wikipedia example]
+
+sub home_prime {
+	local ($n)=@_;
+	while (1){
+		$n=&factors($n);
+		(is_prime($n)) && last;
+	}
+	return $n;
+}
+
+
+sub factors {
+	#--return concatenated prime factors of a number n 
+	local ($n)=@_;
+	local @primes=sieve_primes($n);
+	local $retstring="";
+	
+	if (is_prime($n)){
+		return $n;
+	}
+	else {
+		foreach $prime (sort{$a<=>$b} @primes){
+			while ( ($n % $prime) == 0){
+				$n /= $prime;
+				$retstring .= $prime;
+			}
+		}
+	}
+	return $retstring;	
+}
diff --git a/challenge-168/steve-g-lynn/raku/ch-1.p6 b/challenge-168/steve-g-lynn/raku/ch-1.p6
index ace5c647e1..9610889cf2 100755
--- a/challenge-168/steve-g-lynn/raku/ch-1.p6
+++ b/challenge-168/steve-g-lynn/raku/ch-1.p6
@@ -1,8 +1,11 @@
 #!/usr/bin/raku
 
 my %saveprimes=();
+my ($p1,$p2,$p3)=(3,0,2);
 for ^Inf {
-	my $chk=perrin($_);
+	my $chk=$p1;
+	my $p4=$p1+$p2;
+	$p1=$p2; $p2=$p3;$p3=$p4;
 	(is-prime($chk)) && (%saveprimes{$chk}=1);
 	%saveprimes.elems==13 && last;
 }
@@ -10,36 +13,4 @@ for ^Inf {
 say %saveprimes.keys.sort({.Int});
 
 
-#-- subs
 
-multi sub perrin(0) {3} 
-multi sub perrin(Int $n where ($n>0)){postmult_302(matpow($n))}
-
-#-- subs for fast computation of perrin number using matrix formula
-#-- see wikipedia https://en.wikipedia.org/wiki/Perrin_number
-
-#[0 1 0; 0 0 1; 1 1 0]^n (retain 1st row)
-multi sub matpow(1){ (0,1,0) }
-multi sub matpow(Int $n where ($n>1)) { postmult_010_001_110 (matpow($n-1)) }
-
-# 3x3 matrix * [0 1 0; 0 0 1; 1 1 0] (retain 1st row of product)
-sub postmult_010_001_110 (*@inmatrix){
-	# [a11 a12 a13; a21 a22 a23; a31 a32 a33]*[0 1 0; 0 0 1; 1 1 0]
-	my ($a11,$a12,$a13)=@inmatrix; #just need 1st row
-	
-	my $b11=$a13;
-	my $b12=$a11+$a13;
-	my $b13=$a12;
-
-	return ($b11,$b12,$b13) #-- return just 1st row
-}
-
-# 3x3 matrix * [3;0;2] retain 1st element of product
-sub postmult_302 (*@inmatrix){
-	my ($a11,$a12,$a13)=@inmatrix; #-- just need 1st row
-	# [a11 a12 a13; a21 a22 a23; a31 a32 a33]*[3;0;2]
-	#
-	my $b1=$a11*3+$a13*2; #-- 1st element
-	
-	return $b1;
-}
diff --git a/challenge-168/steve-g-lynn/raku/ch-2.p6 b/challenge-168/steve-g-lynn/raku/ch-2.p6
new file mode 100755
index 0000000000..71fa044657
--- /dev/null
+++ b/challenge-168/steve-g-lynn/raku/ch-2.p6
@@ -0,0 +1,61 @@
+#!/usr/bin/raku
+
+say homeprime(16);
+# 31636373
+#-- works but very slow: time real 0m59.301s user 0m58.334s sys 0m0.773s
+#-- on MacBook Air running Linux FC36
+
+#-- sub for home prime
+
+sub homeprime(Int $n){
+	my $ncopy=$n;
+	while (1) {
+		$ncopy=factor($ncopy).Int;
+		($ncopy.is-prime) && last;
+	}
+	return $ncopy;
+}
+
+#--sub for factorizing
+
+multi sub factor (1) {1}
+
+multi sub factor (Int $n where $n > 1){
+#-- returns string concatenation of prime factors
+	my @primes=prime_sieve($n);
+	my $retstring="";
+	my $ncopy=$n;
+
+	($n.is-prime) && (return $n);	
+	
+	for @primes -> $prime {
+		while ( ($ncopy % $prime)==0) {
+			$ncopy /= $prime;
+			$retstring ~= $prime;
+		}
+	}
+	return $retstring;
+}
+
+#--sub for sieve of Eratosthenes
+#-- (algorihm from wikipedia)
+sub prime_sieve(Int $n where $n > 1){
+	my @a = 2..$n;
+	my (%retval=(),@retval=());
+	for (@a) -> $i {
+		%retval{$i}=1;
+	}
+	my @i= 2..round(sqrt($n));
+	for @i -> $i {
+		loop ( my $j=($i*$i); $j <= $n; $j += $i){
+			%retval{$j}=0;			
+		}
+	}
+	my @k = %retval.keys; 
+	for @k -> $k {
+		if (%retval{$k}==1) {
+			push @retval, $k;
+		}
+	}
+	return (@retval.sort:{$^a <=> $^b});	
+}
-- 
cgit 


From e4536342eb74eb731807602c65588d0895ef9505 Mon Sep 17 00:00:00 2001
From: Julien Fiegehenn <simbabque@cpan.org>
Date: Wed, 8 Jun 2022 22:33:00 +0100
Subject: challenge 168, in Perl

Written with Github Copilot
---
 challenge-168/julien-fiegehenn/perl/ch-1.pl | 48 ++++++++++++++++++
 challenge-168/julien-fiegehenn/perl/ch-2.pl | 78 +++++++++++++++++++++++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 challenge-168/julien-fiegehenn/perl/ch-1.pl
 create mode 100644 challenge-168/julien-fiegehenn/perl/ch-2.pl

(limited to 'challenge-168')

diff --git a/challenge-168/julien-fiegehenn/perl/ch-1.pl b/challenge-168/julien-fiegehenn/perl/ch-1.pl
new file mode 100644
index 0000000000..2e331a2415
--- /dev/null
+++ b/challenge-168/julien-fiegehenn/perl/ch-1.pl
@@ -0,0 +1,48 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use feature 'say';
+
+# Task 1: Perrin Prime
+# Submitted by: Roger Bell_West
+# The Perrin sequence is defined to start with [3, 0, 2]; after that, term N is the sum of terms N-2 and N-3. (So it continues 3, 2, 5, 5, 7, ….)
+
+# A Perrin prime is a number in the Perrin sequence which is also a prime number.
+
+# Calculate the first 13 Perrin Primes.
+
+# f(13) = [2, 3, 5, 7, 17, 29, 277, 367, 853, 14197, 43721, 1442968193, 792606555396977]
+
+sub is_prime {
+    my $n = shift;
+    return 0 if $n < 2;
+    return 1 if $n == 2;
+    return 0 if $n % 2 == 0;
+    for (my $i = 3; $i <= sqrt($n); $i += 2) {
+        return 0 if $n % $i == 0;
+    }
+    return 1;
+}
+
+sub perrin_primes {
+    my $n = shift;
+    my %primes = map { $_ => 1 } 2, 3;
+    my @perrin = (3, 0, 2);
+    my $i = 3;
+    while (keys %primes < $n) {
+        $perrin[$i] = $perrin[$i - 2] + $perrin[$i - 3];
+        if (is_prime($perrin[$i])) {
+            $primes{$perrin[$i]} = 1;
+        }
+        $i++;
+    }
+    return sort { $a <=> $b } keys %primes;
+}
+
+my @primes = perrin_primes(13);
+say "@primes";
+
+__END__
+use Test::More;
+is_deeply \@primes, [2, 3, 5, 7, 17, 29, 277, 367, 853, 14197, 43721, 1442968193, 792606555396977];
+done_testing;
\ No newline at end of file
diff --git a/challenge-168/julien-fiegehenn/perl/ch-2.pl b/challenge-168/julien-fiegehenn/perl/ch-2.pl
new file mode 100644
index 0000000000..9e9812d039
--- /dev/null
+++ b/challenge-168/julien-fiegehenn/perl/ch-2.pl
@@ -0,0 +1,78 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+use feature 'say';
+
+# Task 2: Home Prime
+# Submitted by: Mohammad S Anwar
+# You are given an integer greater than 1.
+
+# Write a script to find the home prime of the given number.
+
+# In number theory, the home prime HP(n) of an integer n greater than 1 is the prime number obtained by repeatedly factoring the increasing concatenation of prime factors including repetitions.
+
+# Further information can be found on Wikipedia and OEIS.
+
+# Example
+# As given in the Wikipedia page,
+
+# HP(10) = 773, as 10 factors as 2×5 yielding HP10(1) = 25, 25 factors as 5×5 yielding HP10(2) = HP25(1) = 55, 55 = 5×11 implies HP10(3) = HP25(2) = HP55(1) = 511, and 511 = 7×73 gives HP10(4) = HP25(3) = HP55(2) = HP511(1) = 773, a prime number.
+
+# written with github copilot
+
+# calculate the prime factors of a number
+sub prime_factors {
+    my $n = shift;
+    my @factors = ();
+    my $i = 2;
+    while ($n > 1) {
+        while ($n % $i == 0) {
+            push @factors, $i;
+            $n /= $i;
+        }
+        $i++;
+    }
+    return @factors;
+}
+
+sub is_prime {
+    my $n = shift;
+    return 0 if $n < 2;
+    return 1 if $n == 2;
+    return 0 if $n % 2 == 0;
+    for (my $i = 3; $i <= sqrt($n); $i += 2) {
+        return 0 if $n % $i == 0;
+    }
+    return 1;
+}
+
+# calculate the home prime of a number
+# In number theory, the home prime HP(n) of an integer n greater than 1 is the prime number obtained by repeatedly factoring the increasing concatenation of prime factors including repetitions.
+sub home_prime {
+    my $n = shift;
+
+    return $n if is_prime($n);
+    return home_prime(join '', prime_factors($n));
+}
+
+# a version of home_prime that produces debug output at every step
+sub home_prime_debug {
+    my $n = shift;
+
+    say "n = $n";
+    return $n if is_prime($n);
+    my @factors = prime_factors($n);
+    say "factors = @factors";
+    return home_prime_debug(join '', @factors);
+}
+
+__END__
+
+use Test::More;
+is_deeply [prime_factors(10)], [2, 5];
+is_deeply [prime_factors(13)], [13];
+is_deeply [prime_factors(14)], [2, 7];
+
+is home_prime(10), 773;
+is home_prime_debug(10), 773;
+done_testing;
\ No newline at end of file
-- 
cgit 


From dc6d3cd6cc5fee7911b59bee164cdf4bf32ee69f Mon Sep 17 00:00:00 2001
From: Roger Bell_West <roger@firedrake.org>
Date: Thu, 9 Jun 2022 09:15:38 +0100
Subject: Blog post for challenge #168

---
 challenge-168/roger-bell-west/blog.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 challenge-168/roger-bell-west/blog.txt

(limited to 'challenge-168')

diff --git a/challenge-168/roger-bell-west/blog.txt b/challenge-168/roger-bell-west/blog.txt
new file mode 100644
index 0000000000..aca56403ca
--- /dev/null
+++ b/challenge-168/roger-bell-west/blog.txt
@@ -0,0 +1 @@
+https://blog.firedrake.org/archive/2022/06/The_Weekly_Challenge_168__At_Home_with_the_Perrins.html
-- 
cgit 


From dceb0fcbb748fd8444bb8bf0a1589bc672d2d334 Mon Sep 17 00:00:00 2001
From: Stephen Lynn <bizlsg@localhost.localdomain>
Date: Thu, 9 Jun 2022 19:03:02 +0800
Subject: improved raku version added julia example for ch-2

---
 challenge-168/steve-g-lynn/julia/ch-2.jl | 15 +++++++
 challenge-168/steve-g-lynn/raku/ch-2.p6  | 69 +++++++++++++++++++++-----------
 2 files changed, 61 insertions(+), 23 deletions(-)
 create mode 100755 challenge-168/steve-g-lynn/julia/ch-2.jl

(limited to 'challenge-168')

diff --git a/challenge-168/steve-g-lynn/julia/ch-2.jl b/challenge-168/steve-g-lynn/julia/ch-2.jl
new file mode 100755
index 0000000000..19d4c7d498
--- /dev/null
+++ b/challenge-168/steve-g-lynn/julia/ch-2.jl
@@ -0,0 +1,15 @@
+#! /usr/bin/julia
+
+using Primes
+
+function homeprime(n::Int64)
+	ncopy=n
+	while (!isprime(ncopy))
+		ncopy=parse(Int64,join(factor(Vector,ncopy)))
+	end
+	return ncopy
+end
+
+println(homeprime(16))
+#31636373
+
diff --git a/challenge-168/steve-g-lynn/raku/ch-2.p6 b/challenge-168/steve-g-lynn/raku/ch-2.p6
index 71fa044657..b4183fd6d3 100755
--- a/challenge-168/steve-g-lynn/raku/ch-2.p6
+++ b/challenge-168/steve-g-lynn/raku/ch-2.p6
@@ -2,8 +2,7 @@
 
 say homeprime(16);
 # 31636373
-#-- works but very slow: time real 0m59.301s user 0m58.334s sys 0m0.773s
-#-- on MacBook Air running Linux FC36
+#-- works but slow
 
 #-- sub for home prime
 
@@ -22,7 +21,8 @@ multi sub factor (1) {1}
 
 multi sub factor (Int $n where $n > 1){
 #-- returns string concatenation of prime factors
-	my @primes=prime_sieve($n);
+#	my @primes=prime_sieve($n);
+	my @primes=find_primes($n);
 	my $retstring="";
 	my $ncopy=$n;
 
@@ -37,25 +37,48 @@ multi sub factor (Int $n where $n > 1){
 	return $retstring;
 }
 
-#--sub for sieve of Eratosthenes
-#-- (algorihm from wikipedia)
-sub prime_sieve(Int $n where $n > 1){
-	my @a = 2..$n;
-	my (%retval=(),@retval=());
-	for (@a) -> $i {
-		%retval{$i}=1;
-	}
-	my @i= 2..round(sqrt($n));
-	for @i -> $i {
-		loop ( my $j=($i*$i); $j <= $n; $j += $i){
-			%retval{$j}=0;			
-		}
-	}
-	my @k = %retval.keys; 
-	for @k -> $k {
-		if (%retval{$k}==1) {
-			push @retval, $k;
-		}
+multi sub find_primes(Int $n where $n <= 13) {
+	my @primes=(2,3,5,7,11,13);
+	my @retval=();
+	for @primes -> $prime {
+		($prime < $n) && (push @retval, $prime);
 	}
-	return (@retval.sort:{$^a <=> $^b});	
+	return (@retval.sort);
 }
+
+multi sub find_primes(Int $n where $n > 13) {
+#-- naive approach by trial factorization    
+    my @primes=(3,7,11,13);
+    
+    my $i=13;
+    
+    while ($i < $n) {
+    	#-- count only odd numbers not ending in 5. Take 4 at a time.
+        my @testarray=();
+    
+    	(($i+4) < $n) && (push @testarray, ($i+4));
+        (($i+6) < $n) && (push @testarray, ($i+6));
+        (($i+8) < $n) && (push @testarray, ($i+8));
+        (($i+10) < $n) && (push @testarray, ($i+10));
+
+        while (@testarray.elems > 0) {
+            my $testitem=shift(@testarray);
+            unless ((($testitem % 6)==1) || (($testitem % 6)==5)) {
+            #-- use the property that prime numbers above 5 are 6k+1 or 6k-1  
+            	next;
+            }
+            for @primes -> $prime {
+                ($prime > sqrt($testitem)) && last;
+                (($testitem % $prime)==0) && last;
+            }
+            push @primes, $testitem;
+        }
+        $i += 10;
+    }
+
+    splice(@primes,0,1, <2 3 5>); #-- left out 2 and 5 earlier to avoid
+    				  #   unnecessary redundant factorizing
+    return (@primes.sort);
+}
+
+
-- 
cgit 


From 24bce6c7bbb60c50ed3bead06e8a16da9db8eeef Mon Sep 17 00:00:00 2001
From: Humberto Massa <humbertomassa@gmail.com>
Date: Thu, 9 Jun 2022 12:23:22 -0300
Subject: Answer to challenge 168 by Massa, Humberto

---
 challenge-168/massa/raku/ch-1.raku |  2 ++
 challenge-168/massa/raku/ch-2.raku | 28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 challenge-168/massa/raku/ch-1.raku
 create mode 100644 challenge-168/massa/raku/ch-2.raku

(limited to 'challenge-168')

diff --git a/challenge-168/massa/raku/ch-1.raku b/challenge-168/massa/raku/ch-1.raku
new file mode 100644
index 0000000000..d8fd9a0b66
--- /dev/null
+++ b/challenge-168/massa/raku/ch-1.raku
@@ -0,0 +1,2 @@
+use v6;
+(3, 0, 2, * + * + 0 * * ... *).grep(*.is-prime)[^20].sort.unique[^13].say
diff --git a/challenge-168/massa/raku/ch-2.raku b/challenge-168/massa/raku/ch-2.raku
new file mode 100644
index 0000000000..535eaa16fa
--- /dev/null
+++ b/challenge-168/massa/raku/ch-2.raku
@@ -0,0 +1,28 @@
+use v6;
+
+my sub factors(int \x is copy) {
+  my int $possible-factor = 2;
+  gather {
+    while x > 1 {
+      if $possible-factor.is-prime && x %% $possible-factor {
+        take $possible-factor;
+        x div= $possible-factor
+      } else {
+        Nil until is-prime ++$possible-factor
+      }
+    }
+  }
+}
+
+my sub hp(int \x is copy) {
+  loop {
+    given +[~] factors x {
+      .return if .is-prime;
+      x = $_
+    }
+  }
+}
+
+sub MAIN(Int() \n where * > 1) {
+  say hp n
+}
-- 
cgit 


From 26d2ce2e72a752e3e622f9e0717c6b95fe205115 Mon Sep 17 00:00:00 2001
From: Humberto Massa <humbertomassa@gmail.com>
Date: Thu, 9 Jun 2022 13:10:04 -0300
Subject: `head()` was the answer... :-)

---
 challenge-168/massa/raku/ch-1.raku | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'challenge-168')

diff --git a/challenge-168/massa/raku/ch-1.raku b/challenge-168/massa/raku/ch-1.raku
index d8fd9a0b66..2fbde00b8c 100644
--- a/challenge-168/massa/raku/ch-1.raku
+++ b/challenge-168/massa/raku/ch-1.raku
@@ -1,2 +1,2 @@
 use v6;
-(3, 0, 2, * + * + 0 * * ... *).grep(*.is-prime)[^20].sort.unique[^13].say
+(3, 0, 2, * + * + 0 * * ... *).grep(*.is-prime).unique.head(13).sort.say
-- 
cgit 


From 0e1f5b17707b5151487904b00ea69b3ba3b1e961 Mon Sep 17 00:00:00 2001
From: Lubos Kolouch <lubos@kolouch.net>
Date: Thu, 9 Jun 2022 21:15:40 +0200
Subject: feat(challenge-168/lubos-kolouch/p[erl,ython]/ch-1.p[ly]): Challenge
 168 Task 1 LK Perl Python

---
 challenge-168/lubos-kolouch/perl/ch-1.pl   | 33 +++++++++++++++++++++++++
 challenge-168/lubos-kolouch/python/ch-1.py | 39 ++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 challenge-168/lubos-kolouch/perl/ch-1.pl
 create mode 100644 challenge-168/lubos-kolouch/python/ch-1.py

(limited to 'challenge-168')

diff --git a/challenge-168/lubos-kolouch/perl/ch-1.pl b/challenge-168/lubos-kolouch/perl/ch-1.pl
new file mode 100644
index 0000000000..956d2822e4
--- /dev/null
+++ b/challenge-168/lubos-kolouch/perl/ch-1.pl
@@ -0,0 +1,33 @@
+package main;
+use strict;
+use warnings;
+use Math::Prime::Util qw(is_prime);
+
+sub generate_perrin_sequence {
+    my $n               = shift;
+    my @perrin_sequence = ( 3, 0, 2 );
+
+    my %perrin_primes;
+
+    while ( scalar keys %perrin_primes < $n ) {
+        my $next_number = $perrin_sequence[-3] + $perrin_sequence[-2];
+        push @perrin_sequence, $next_number;
+        $perrin_primes{$next_number} = 1 if is_prime($next_number);
+    }
+
+    my @primes = sort { $a <=> $b } keys %perrin_primes;
+
+    return \@primes;
+}
+
+use Test::More;
+
+is_deeply(
+    generate_perrin_sequence(13),
+    [   2, 3, 5, 7, 17, 29, 277, 367, 853, 14197, 43721, 1442968193,
+        792606555396977
+    ]
+);
+
+done_testing;
+1;
diff --git a/challenge-168/lubos-kolouch/python/ch-1.py b/challenge-168/lubos-kolouch/python/ch-1.py
new file mode 100644
index 0000000000..8c8790c5dc
--- /dev/null
+++ b/challenge-168/lubos-kolouch/python/ch-1.py
@@ -0,0 +1,39 @@
+""" Challenge 168 Task 1 LK Python """
+
+from sympy import isprime
+
+
+def generate_perrin_primes(n: int) -> list:
+    """
+    Generate all primes up to n using the Perrin sequence.
+    """
+    perrin_sequence = [3, 0, 2]
+
+    perrin_primes: dict = {}
+
+    while len(perrin_primes.keys()) < n:
+
+        next_number = perrin_sequence[-3] + perrin_sequence[-2]
+        perrin_sequence.append(next_number)
+
+        if isprime(next_number):
+            perrin_primes[next_number] = True
+
+    return sorted(perrin_primes.keys())
+
+
+assert generate_perrin_primes(13) == [
+    2,
+    3,
+    5,
+    7,
+    17,
+    29,
+    277,
+    367,
+    853,
+    14197,
+    43721,
+    1442968193,
+    792606555396977,
+]
-- 
cgit 


From 53521e94fb339868c5b875f629ba3097166e50d3 Mon Sep 17 00:00:00 2001
From: Jörg Sommrey <28217714+jo-37@users.noreply.github.com>
Date: Mon, 6 Jun 2022 19:50:54 +0200
Subject: Solution to task 1

---
 challenge-168/jo-37/perl/ch-1.pl | 155 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 155 insertions(+)
 create mode 100755 challenge-168/jo-37/perl/ch-1.pl

(limited to 'challenge-168')

diff --git a/challenge-168/jo-37/perl/ch-1.pl b/challenge-168/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..8351305463
--- /dev/null
+++ b/challenge-168/jo-37/perl/ch-1.pl
@@ -0,0 +1,155 @@
+#!/usr/bin/perl -s
+
+use v5.16;
+use Test2::V0 '!array';
+use bigint;
+use List::Gen qw(:iterate :zip :source);
+use List::Util qw(product);
+use Math::Prime::Util qw(is_prime gcd);
+use experimental qw(signatures postderef);
+
+our ($tests, $examples, $iv, $f);
+$iv ||= '3, 0, 2';
+$f ||= '1, 1';
+
+run_tests() if $tests || $examples;	# does not return
+
+die <<EOS unless @ARGV;
+usage: $0 [-examples] [-tests] [-f=F1,...,Fl] [-iv=S1,...Sk] [N]
+
+-examples
+    run the examples from the challenge
+ 
+-tests
+    run some tests
+
+-f=F1,...,Fl
+    Coefficients for the linear recurrence relation.
+
+-iv=S1,...,Sk
+    Starting values for the generated sequence.
+
+N
+    Print the first N prime numbers from the generated sequence.
+
+    The sequence starts with the values S1,...,Sk and has the
+    linear recurrence relation:
+    S(n) = F(1) * S(n - k) + ... + F(k) * S(n - 1) for n > k.
+    Selecting unique primes from this sequence.
+
+Some known prime sequences:
+IV=0,1   F=1,1: Fibonacci
+IV=2,1   F=1,1: Lucas
+IV=1,1,1 F=1,1: Padovan
+IV=3,0,2 F=1,1: Perrin (default)
+IV=0,1   F=1,2: Pell
+IV=0,1   F=2,1: Jacobsthal
+
+CAUTION: Improper choice of IV and F will cause an endless loop!
+
+EOS
+
+
+### Input and Output
+
+main: {
+    # Explicit conversion to Math::BigInt is required for a set of
+    # variables so that all newly generated values inherit therefrom.
+    # Linear factors:
+    my $f = [map Math::BigInt->new($_), split /, */, $f];
+    # Initial values:
+    my $iv = [split /, */, $iv];
+
+    # "say(n)" prints the first n generated elements.
+    lin_recur_primes($iv, $f)->say(shift);
+}
+
+
+### Implementation
+
+# The solution to task 2 from challenge 154 with different starting
+# values could be reused to solve this task.  But this would by boring
+# and thus the task will be generalized here.
+#
+# The excellent Math::Prime::Util ennobles List::Gen by referencing it in
+# the "SEE ALSO" section.  Indeed, it looks very cool but comes with a
+# serious flaw: There has not been any development for over 10 years and
+# one of the tests is broken.  Needed "--force" to install. IMHO the
+# test result is ok, but the expected outcome is not.
+# "Failed test 'map & \(1 .. 3), 1 .. 2'"
+#
+# Building a generator for a sequence having the initial values
+# S(1),...,S(k) and a recurrence relation defined by a linear
+# combination of preceding elements:
+# S(n) = F(1) * S(n - k) + ... + F(k) * S(n - 1) for n > k.
+# and taking unique primes thereof.
+#
+sub lin_recur_primes ($s, $f) {
+
+    # Lazily extend the initial sequence using the recurrence relation.
+    ($s + iterate {($s = [$s->@[1 .. $#$s],
+                    tuples($f, $s)->map('product @$_')->sum])->[-1]
+        })->uniq->filter(sub {is_prime $_});
+}
+
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+
+        # "take" returns the given number of elements.
+        is lin_recur_primes([3, 0, 2], [1, 1])->take(13),
+        [3, 2, 5, 7, 17, 29, 277, 367, 853, 14197, 43721, 1442968193,
+            792606555396977], 'task 1';
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        # "get" accesses elements by a zero-based index.  Thus "get(15)"
+        # is *three* behind the last from "take(13)".
+        is lin_recur_primes([3, 0, 2], [1, 1])->get(15),
+        '22584751787583336797527561822649328254745329',
+        'Perrin prime from http://oeis.org/A074788';
+
+        is lin_recur_primes([0, 1], [1, 1])->take(11),
+        [2, 3, 5, 13, 89, 233, 1597, 28657, 514229, 433494437,
+            2971215073],
+            'Fibonacci primes from Wiki';
+
+        is lin_recur_primes([1, 1, 1], [1, 1])->take(12),
+        [2, 3, 5, 7, 37, 151, 3329, 23833, 13091204281, 3093215881333057,
+            1363005552434666078217421284621279933627102780881053358473,
+            1558877695141608507751098941899265975115403618621811951868598809164180630185566719],
+            'Padovan primes from Wiki';
+        
+        is lin_recur_primes([2, 1], [1, 1])->take(15),
+        [2, 3, 7, 11, 29, 47, 199, 521, 2207, 3571, 9349, 3010349,
+            54018521, 370248451, 6643838879],
+            'Lucas primes from Wiki';
+
+        is lin_recur_primes([3, 1], [1, 1])->take(20),
+        [3, 5, 23, 37, 97, 157, 1741, 11933, 50549, 214129, 560597,
+            16276621, 180510493, 398386576261, 1042989597313,
+            41305516996050613, 174972977841043309, 13300248193487978669,
+            238663270054423392193, 624828552868675407173],
+            'A091157';
+
+        is lin_recur_primes([0, 1], [1, 2])->take(8),
+        [2, 5, 29, 5741, 33461, 44560482149, 1746860020068409,
+            68480406462161287469],
+            'Pell primes from Wiki';
+
+        is lin_recur_primes([0, 1], [2, 1])->take(15),
+        [3, 5, 11, 43, 683, 2731, 43691, 174763, 2796203, 715827883,
+            2932031007403, 768614336404564651, 201487636602438195784363,
+            845100400152152934331135470251,
+            56713727820156410577229101238628035243],
+            'Jacobsthal primes from Wiki';
+	}
+
+    done_testing;
+    exit;
+}
-- 
cgit