MathDB

N3

Part of 2021 Balkan MO Shortlist

Problems(1)

BMO Shortlist 2021 N3

Source: BMO Shortlist 2021

5/8/2022
Let nn be a positive integer. Determine, in terms of nn, the greatest integer which divides every number of the form p+1p + 1, where p≡2p \equiv 2 mod 33 is a prime number which does not divide nn.
Balkanshortlist2021number theorycongruence