In this paper we present a generalization of Faulhaber's formula to
sums of arbitrary complex powers
.
These summation
formulas for sums of the form
and
,
where
and
,
are based on a series acceleration involving Stirling numbers of the
first kind. While it is well-known that the corresponding expressions
obtained from the Euler-Maclaurin summation formula diverge, our summation
formulas are all very rapidly convergent.