MathDB
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 n{1,2,3,,2009} n\in\{1,2,3,\ldots,2009\} such that 4n^6 \plus{} n^3 \plus{} 5 is divisible by 7 7.