MathDB
Show that $P(n)\in\mathbb{Z}, \forall n\in\mathbb{N}$

Source: Moldova TST 1997

August 8, 2023
algebrapolynomial

Problem Statement

Let P(X)P(X) be a polynomial with real coefficients such that {P(n)}1n,nN\{P(n)\}\leq\frac{1}{n}, \forall n\in\mathbb{N}, where {a}\{a\} is the fractional part of the number aa. Show that P(n)Z,nNP(n)\in\mathbb{Z}, \forall n\in\mathbb{N}.