ζ⁡(s,a)=1as+1(1+a)s⁢(12+1+as-1)+∑k=1n(s+2⁢k-22⁢k-1)⁢B2⁢k2⁢k⁢1(1+a)s+2⁢k-1-(s+2⁢n2⁢n+1)⁢∫1∞B~2⁢n+1⁡(x)(x+a)s+2⁢n+1⁢ⅆ⁡x,