A009753 Expansion of tan(x)/(1+x).

0, 1, -2, 8, -32, 176, -1056, 7664, -61312, 559744, -5597440, 61925632, -743107584, 9682766848, -135558735872, 2035284795392, -32564556726272, 553807329689600, -9968531934412800, 189431195638956032, -3788623912779120640

Offset

0,3

Links

G. C. Greubel, Table of n, a(n) for n = 0..445

Formula

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

Maple

G(x):= tan(x)/(1+x): f[0]:=G(x): for n from 1 to 21 do f[n]:=diff(f[n-1], x) od: x:=0: seq(f[n], n=0..20); # Zerinvary Lajos, Apr 03 2009

Mathematica

CoefficientList[Series[Tan[x]/(1 + x), {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 24 2015 *)

Prog

(PARI) x='x+O('x^30); concat([0], Vec(serlaplace(tan(x)/(1+x)))) \\ G. C. Greubel, Feb 12 2018

Crossrefs

Cf. A049471 (tan(1)).

Sequence in context: A137975 A051636 A081561 * A141202 A081358 A294506

Adjacent sequences: A009750 A009751 A009752 * A009754 A009755 A009756

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved