CMOQR 2016 Problem 1

(a) Find all positive integers $n$ such that $11|(3^n + 4^n)$ .

(b) Find all positive integers $n$ such that $31|(4^n + 7^n + 20^n)$ .

Dataset text AI-MO AoPS. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.