A009420 Expansion of log(1+x)*exp(tanh(x)).

0, 1, 1, 2, -8, -11, -19, 846, -1896, -111, -228159, 2453010, -11353440, 173733429, -3565851587, 41759789358, -501111404080, 9579604130881, -176443305192159, 2870638703204994, -53275482352387864, 1134671091039714069

Offset: 0

Author

R. H. Hardin

Keywords

• sign
• easy

Programs

Mathematica

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

Formula

a(n) ~ (n-1)! * (-1)^(n+1) * exp(-tanh(1)). - Vaclav Kotesovec, Jan 23 2015

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997