IOM 2021, Блиц — Задача 4

The Blitz-contest of IOM-2021

Условие

Find all numbers of the form $pq$, where $p$ and $q$ are prime numbers and $pq$ divides $7^p + 7^q$.

If there are multiple answers, they should be entered each in its own field; add more fields with the “+” button.

Отговори

Решение

Оригинал в Архива: iom-2021-blitz-tasks-eng.pdf · официални решения: iom-2021-blitz-answers-eng.pdf