MathDB
CIIM 2011 Problem 2

Source:

June 9, 2016
CIIM 2011undergraduate

Problem Statement

Let kk be a positive integer, and let aa be an integer such that a2a-2 is a multiple of 77 and a61a^6-1 is a multiple of 7k7^k.
Prove that (a+1)61(a + 1)^6-1 is also a multiple of 7k7^k.