MathDB
a^k+n are all composite numbers

Source: China second round 2018 (B) Q4

June 22, 2019
number theory

Problem Statement

Prove that for any integer a2a \ge 2 and positive integer n,n, there exist positive integer kk such that ak+1,ak+2,,ak+na^k+1,a^k+2,\ldots,a^k+n are all composite numbers.