Ruby code - 18 lines

Link:

Ruby, pasted on Aug 27:

def is_prime(n)
  return false if n <= 1
  2.upto(Math.sqrt(n).to_i) do |x|
    return false if n%x == 0
  end
  true
end

arr = []

for i in 0..1000000
	i_arr = i.to_s.split(//)
	if (is_prime(i) == true and is_prime(i_arr.reverse.join.to_i) == true) and i != i_arr.reverse.join.to_i
		arr << i
		puts i
	end
end

Output:

Create a new paste based on this one

Comments: