MathDB
Classical problem on integer polynomial

Source: Bulgaria National Olympiad 2023 P3

April 8, 2023
algebrapolynomialabstract algebrainequalities

Problem Statement

Let f(x)f(x) be a polynomial with positive integer coefficients. For every nNn\in\mathbb{N}, let a1(n),a2(n),,an(n)a_{1}^{(n)}, a_{2}^{(n)}, \dots , a_{n}^{(n)} be fixed positive integers that give pairwise different residues modulo nn and let g(n)=i=1nf(ai(n))=f(a1(n))+f(a2(n))++f(an(n))g(n) = \sum\limits_{i=1}^{n} f(a_{i}^{(n)}) = f(a_{1}^{(n)}) + f(a_{2}^{(n)}) + \dots + f(a_{n}^{(n)}) Prove that there exists a constant MM such that for all integers m>Mm>M we have gcd(m,g(m))>20232023\gcd(m, g(m))>2023^{2023}.