Suppose a and b are positive integers. We all know that aČ+2ab+bČ is a perfect square. Give an example where also aČ+ab+bČ is a perfect square. How many such examples exist?
This question was posed to me more than 20 years back in an inteview of National Talent Search during my high school days. I used to think I had cracked couple of series then. Now based on your ( Charlie, Tomarken & Dej Mar's ) findings looks like their is whole family of numbers. This is great to know.

Posted by Salil
on 20060425 20:53:26 