login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A009088 Expansion of e.g.f. x*cos(tanh(x)), odd powers only. 1
1, -3, 45, -1239, 54873, -3577739, 322495173, -38370542175, 5817952885169, -1093812528874387, 249472828725529437, -67807763939709678951, 21642089202188444732425, -8010884242566625383028251 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..239

MAPLE

seq(coeff(series(factorial(n)*x*cos(tanh(x)), x, n+1), x, n), n=1..30, 2); # Muniru A Asiru, Jul 25 2018

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Cos[Tanh[x]]x, {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Nov 01 2011 *)

PROG

(PARI) x='x+O('x^60); v=Vec(serlaplace(x*cos(tanh(x)))); vector((#v-1)\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 25 2018

CROSSREFS

Sequence in context: A012769 A302106 A241242 * A245066 A187662 A113065

Adjacent sequences:  A009085 A009086 A009087 * A009089 A009090 A009091

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 22 13:49 EDT 2021. Contains 348170 sequences. (Running on oeis4.)