IMO 2016 Shortlist N2
Let τ(n) be the number of positive divisors of n. Let τ1(n) be the number of positive divisors of n which have remainder...
Category: Number Theory
Problem
Let τ(n) be the number of positive divisors of n. Let τ1(n) be the number of positive divisors of n which have remainders 1 when divided by 3. Find all possible integral values of the fraction τ(10n) τ1(10n) .