\[B_{2n}\left(x\right)=(-1)^{n+1}2n\*\int_{0}^{\infty}\frac{\cos\left(2\pi x%
\right)-e^{-2\pi t}}{\cosh\left(2\pi t\right)-\cos\left(2\pi x\right)}t^{2n-1}%
\,\mathrm{d}t,\]