Divisility by 7
Source: Indonesian MO (INAMO) 2009, Day 1, Problem 1
August 8, 2009
modular arithmeticquadraticsalgebrapolynomialnumber theorydivisibility testsnumber theory unsolved
Problem Statement
Find all positive integers such that
4n^6 \plus{} n^3 \plus{} 5
is divisible by .