Prove that if a²+b² is a multiple of ab+1, for positive integer a and b, then (a²+b²)/(ab+1) is a perfect square.

(In reply to re: A start by Brian Smith)

My proof assumed c^2+d^2 wouldn't equal ab+1. It now gives a less powerful result, but still somewhat interesting.

Posted by Gamer on 2007-03-25 01:50:03