Denote by R(N) the integer obtained by reversing the digits of a positive integer N.

Determine the largest integer that is certain to divide N⁴ - (R(N))⁴, with N > R(N), regardless of the choice of N.

(In reply to possible computer solution by Charlie)

I beleve that your program does not address the 4th, or at least the 2nd power.

Posted by Ady TZIDON on 2014-07-22 12:09:02