MathDB

3

Part of 2023 Thailand Online MO

Problems(1)

n!|a^{n!}-1

Source: 2023 Thailand Online MO P3

2/12/2023
Let aa and nn be positive integers such that the greatest common divisor of aa and n!n! is 11. Prove that n!n! divides an!āˆ’1a^{n!}-1.
number theory