MathDB
Bounding Divisibility

Source: 2021 APMO P2

June 9, 2021
algebrapolynomial

Problem Statement

For a polynomial PP and a positive integer nn, define PnP_n as the number of positive integer pairs (a,b)(a,b) such that a<bna<b \leq n and P(a)P(b)|P(a)|-|P(b)| is divisible by nn. Determine all polynomial PP with integer coefficients such that Pn2021P_n \leq 2021 for all positive integers nn.