Question 133
Given integers $x, y \in [2, 100]$, prove that there exists a positive integer $n$ such that the number $x^{2^n} + y^{2^n}$ is composite.
(S. Berlov, A. Belov)
(S. Berlov, A. Belov)
Math Olympiad Vault · MathNet 2009-part-03 — 175 problems (EN–VI)