MathDB
2000 Guts #40: Phi function

Source:

October 25, 2014
functionnumber theoryrelatively prime

Problem Statement

Let ϕ(n)\phi(n) denote the number of positive integers less than or equal to nn and relatively prime to nn. Find all natural numbers nn and primes pp such that ϕ(n)=ϕ(np)\phi(n)=\phi(np).