A009779 Expansion of e.g.f.: tanh(log(1+x))*log(1+x).

0, 0, 2, -6, 14, -20, -36, 336, 720, -38016, 524160, -5448960, 50388480, -465903360, 5010888960, -69353625600, 1155961497600, -20593469030400, 370356373094400, -6695551947571200, 124010190839808000, -2408196729028608000

Offset

0,3

Links

Table of n, a(n) for n=0..21.

Formula

a(n) ~ (n-1)! * (-1)^n. - Vaclav Kotesovec, Jan 24 2015

Mathematica

CoefficientList[Series[(x*(2 + x)*Log[1 + x])/(2 + x*(2 + x)), {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 24 2015 *)
With[{nn=30}, CoefficientList[Series[Tanh[Log[1+x]]*Log[1+x], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Aug 26 2020 *)

Crossrefs

Sequence in context: A067262 A107369 A151731 * A086666 A032383 A014775

Adjacent sequences: A009776 A009777 A009778 * A009780 A009781 A009782

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified and first Mathematica program replaced by Harvey P. Dale, Aug 26 2020

Status

approved