A009648 Expansion of tan(log(1+x))/exp(x).

0, 1, -3, 10, -44, 255, -1841, 15818, -156960, 1762709, -22076535, 304867506, -4600188108, 75280188035, -1327718893749, 25103478695090, -506480711742496, 10860420245412873, -246630317697276235, 5912837973247721914

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Formula

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

Mathematica

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

Crossrefs

Sequence in context: A259352 A205803 A329258 * A007125 A247053 A102911

Adjacent sequences: A009645 A009646 A009647 * A009649 A009650 A009651

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved