a_{2021}n^{2021}+a_{2020}n^{2020}+...+a_1n+a_0 divisible by 2021
Source: 2021 Ukraine NMO 11.1
April 2, 2021
number theory
Problem Statement
It is known that for some integers a2021,a2020,...,a1,a0 the expression
a2021n2021+a2020n2020+...+a1n+a0
is divisible by 2021 for any arbitrary integer n. Is it required that each of the numbers a2021,a2020,...,a1,a0 also divisible by 2021?