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#!/opt/local/bin/lua
--
-- See ../README.md
--
--
-- Run as: lua ch-2.lua
--
local small_primes = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31}
function factorize (num)
local out = {}
for _, prime in ipairs (small_primes) do
while num % prime == 0 do
table . insert (out, prime)
num = num / prime
end
end
if num > 1 then
table . insert (out, num)
end
return (out)
end
function digit_sum (numbers)
local sum = 0
for _, number in pairs (numbers) do
while number > 0 do
sum = sum + number % 10
number = math . floor (number / 10)
end
end
return (sum)
end
local number = 1
local count = 0
while count < 10 do
local factors = factorize (number)
if #factors > 1 then
if digit_sum ({number}) == digit_sum (factors) then
print (number)
count = count + 1
end
end
number = number + 1
end
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