MathDB

for any integer a exists prime p such that 1+a+a^2+...+ a^{p-1} is composite.

Source: 2001 Estonia National Olympiad Final Round grade 12 p4

March 12, 2020

CompositeSum of powersprimenumber theory

Problem Statement

Prove that for any integer

a > 1

there is a prime

p

for which

1+a+a^2+...+ a^{p-1}

is composite.