MathDB
Number of even and odd divisors

Source: Kürschák 1999, problem 1

July 15, 2014
number theory unsolvednumber theory

Problem Statement

For any positive integer mm, denote by di(m)d_i(m) the number of positive divisors of mm that are congruent to ii modulo 22. Prove that if nn is a positive integer, then k=1n(d0(k)d1(k))n.\left|\sum_{k=1}^n \left(d_0(k)-d_1(k)\right)\right|\le n.