A009355 Expansion of log(1+sinh(x))/cosh(x).

0, 1, -1, 0, -4, 40, -181, 896, -8464, 88320, -863041, 9382912, -120330244, 1676579840, -24638823301, 390142722048, -6678730634944, 121851014348800, -2353418855768161, 48123147849826304, -1039698070255280164

Offset

0,5

Links

Table of n, a(n) for n=0..20.

Formula

a(n) ~ (n-1)! * (-1)^(n+1) / (sqrt(2) * (log(1+sqrt(2)))^n). - Vaclav Kotesovec, Jan 23 2015

Mathematica

Log[ 1+Sinh[ x ] ]/Cosh[ x ]
CoefficientList[Series[Log[1 + Sinh[x]]*Sech[x], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)

Crossrefs

Sequence in context: A271013 A163322 A238328 * A355838 A061132 A215717

Adjacent sequences: A009352 A009353 A009354 * A009356 A009357 A009358

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved