What are the positive integers k and m,
if both k^2 + 4m and m^2 + 5k are squares of integers?

P&p solution to list all the possible couples.

(In reply to A solution by broll)

I agree these are both solutions, but using a computer I was able to find at least one more -- one where m != k+1. I'm not going to post it here until I can derive it without my software, as specified by the problem.

Posted by Paul on 2017-02-20 17:41:09