Generalized Bernoulli number
= Generalized Bernoulli number
{title2=$B_{k,\chi}$}
For a <Dirichlet character> $\chi$ of conductor $f$, define the generalized Bernoulli numbers by
$$
\sum_{a=1}^{f}\chi(a)\frac{z e^{az}}{e^{fz}-1}
=\sum_{k\geq0}B_{k,\chi}\frac{z^k}{k!}.
$$
They express special values of <Dirichlet L-functions> at nonpositive integers and occur in the interpolation formula for <Kubota-Leopoldt p-adic L-functions>.