! Copyright (c) 2010 Samuel Tardieu.
-! See http://factorcode.org/license.txt for BSD license.
+! See https://factorcode.org/license.txt for BSD license.
USING: generalizations kernel math math.functions project-euler.common
sequences sets ;
IN: project-euler.265
-! http://projecteuler.net/index.php?section=problems&id=265
+! https://projecteuler.net/index.php?section=problems&id=265
! 2^(N) binary digits can be placed in a circle so that all the N-digit
! clockwise subsequences are distinct.