Zeta Zeta_sub

Zeta_sub() Sub Zeta_sub ( Ret As  Double, X As  Double, Optional Info As  Long  ) Riemann zeta function ζ(x) (Subroutine version) Purpose Computes the Riemann zeta function ζ(x). ζ(s) = Σ1/n^s (for n = 1 to ∞) Parameters [out] Ret Riemann zeta function ζ(x). [in] X Argument x. (X <> 1) [out] Info (Optional) = 0: Successful exit. = -1: The argument X had an illegal value. (X = 1) = 1: Floating point range error. Reference boost/math/special_functions