Question 164
Let $n$ be a positive integer. Prove that there exists a positive integer $m$ such that
$$
3^m + 5^m - 1
$$
is divisible by $7^n$.
$$
3^m + 5^m - 1
$$
is divisible by $7^n$.
MathNet 2023-part-02 — 191 problems (EN–VI) Question 164
Math Olympiad Vault · MathNet 2023-part-02 — 191 problems (EN–VI)