USAMO #1
Posted: Tue Mar 06, 2018 1:02 pm
Prove that there are infinitely many distinct pairs $(a, b)$ of relatively prime integers $a>1$ and $b>1$ such that $a^b+b^a$ is divisible by $a+b$.
This problem was posted once. If you need solution, you can check this out.
http://matholympiad.org.bd/forum/viewto ... =26&t=3976