MathDB
Counting polynomials that reduce to other polynomials

Source: Belarus TST 2024

July 17, 2024
algebrapolynomial

Problem Statement

A positive integer nn is given. Consider all polynomials P(x)=xn+an1xn1++a0P(x)=x^n+a_{n-1}x^{n-1}+\ldots+a_0, whose coefficients are nonnegative integers, not exceeding 100100. Call PP reducible if it can be factored into two non-constant polynomials with nonnegative integer coeffiecients, and irreducible otherwise. Prove that the number of irreducible polynomials is at least twice as big as the number of reducible polynomials. D. Zmiaikou