SPOJ 20713 DIVCNT2 - Counting Divisors (square)
DIVCNT2 - Counting Divisors (square)#sub-linear#dirichlet-generating-functionLet\sigma_0(n)σ0(n)be the number of positive divisors ofnn.For example,\sigma_0(1) = 1σ0(1)=1,\s...