Two Dirichlet's series related to the Divisor Summatory Function and to the Riemann's zeta-function, $\zeta(s)$
Your original observation is easily explained: $d(n)$ is odd if and only if $n$ is a square.
See my response here.
Two Dirichlet's series related to the Divisor Summatory Function and to the Riemann's zeta-function, $\zeta(s)$
Your original observation is easily explained: $d(n)$ is odd if and only if $n$ is a square.
See my response here.