A009644 Expansion of tan(log(1+x))*exp(x).

0, 1, 1, 4, -4, 55, -349, 3176, -31536, 356981, -4486515, 62124676, -939083124, 15387231899, -271629760609, 5139109612040, -103734448063424, 2225145262126601, -50544116286741191, 1212003840479789476

Offset

0,4

Links

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

Formula

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

Mathematica

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

Crossrefs

Sequence in context: A364763 A367891 A322099 * A196180 A369752 A156483

Adjacent sequences: A009641 A009642 A009643 * A009645 A009646 A009647

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved