MathDB
Purple Comet 2016 HS Problem 24

Source:

April 12, 2018
Purple Comet

Problem Statement

Find the largest prime pp such that pp divides 2p+1+3p+1+5p+1+7p+12^{p+1} + 3^{p+1} + 5^{p+1} + 7^{p+1}.