A009356 Expansion of log(1+sinh(x))/exp(x).

0, 1, -3, 9, -32, 140, -757, 4963, -38376, 341664, -3438641, 38576747, -477118600, 6447914668, -94515392805, 1493405394411, -25300960235504, 457490990665952, -8793604786338049, 179039287811168755, -3849069823206873888

Offset: 0

Author

R. H. Hardin

Keywords

• sign
• easy

Programs

Mathematica

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

Formula

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

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997