feat(challenge-147/lubos-kolouch/perl,python/): Challenge 147 LK Perl Python

2 files changed, 46 insertions, 0 deletions

diff --git a/challenge-147/lubos-kolouch/python/ch-1.py b/challenge-147/lubos-kolouch/python/ch-1.py
new file mode 100644
index 0000000000..49e8c707d2
--- /dev/null
+++ b/challenge-147/lubos-kolouch/python/ch-1.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from sympy import isprime
+
+
+def left_truncatable_primes(n):
+    primes = []
+    queue = list(map(str, range(1, 10)))  # we start from single-digit primes
+    while len(primes) < n:
+        num_str = queue.pop(0)
+        if isprime(int(num_str)):
+            primes.append(int(num_str))
+            # adding digits to the end to try to form the next primes
+            for i in range(10):
+                queue.append(num_str + str(i))
+    return primes[:n]
+
+
+print(left_truncatable_primes(20))
diff --git a/challenge-147/lubos-kolouch/python/ch-2.py b/challenge-147/lubos-kolouch/python/ch-2.py
new file mode 100644
index 0000000000..bd1577bd45
--- /dev/null
+++ b/challenge-147/lubos-kolouch/python/ch-2.py
@@ -0,0 +1,26 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import math
+
+
+def is_pentagonal(num):
+    return (math.sqrt(24 * num + 1) + 1) % 6 == 0
+
+
+def pentagonal_numbers():
+    index = 1
+    pentagonal_nums = []
+    while True:
+        pentagonal_num = index * (3 * index - 1) // 2
+        pentagonal_nums.append(pentagonal_num)
+        for j in range(index - 1, 0, -1):
+            if is_pentagonal(pentagonal_num - pentagonal_nums[j - 1]) and is_pentagonal(
+                pentagonal_num + pentagonal_nums[j - 1]
+            ):
+                return pentagonal_nums[j - 1], pentagonal_num
+        index += 1
+
+
+pair = pentagonal_numbers()
+print(f"Pair of Pentagon Numbers: {pair[0]}, {pair[1]}")