MathDB
Polynomial values contain some contiguous subsequence sum

Source: APMO 2020 Problem 4

June 9, 2020
algebrapolynomialAPMO

Problem Statement

Let Z\mathbb{Z} denote the set of all integers. Find all polynomials P(x)P(x) with integer coefficients that satisfy the following property:
For any infinite sequence a1a_1, a2a_2, \dotsc of integers in which each integer in Z\mathbb{Z} appears exactly once, there exist indices i<ji < j and an integer kk such that ai+ai+1++aj=P(k)a_i +a_{i+1} +\dotsb +a_j = P(k).