Determine all possible pair(s) (X, Y), with X being a prime and Y being a positive integer, that satisfy this equation:

(X-1)! + 1 = X^Y

http://perplexus.info/show.php?pid=6393&cid=42523

Here we were specifically concerned with any perfect square, not just a power of X.  I tried to prove there were few solutions.  Could similar methods work here?

Note: if Y is even we can use the same difference of squares idea.

Posted by Jer on 2009-04-25 01:39:08