login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A009807 Expansion of tanh(tan(sin(x))). 0
1, -1, -7, 167, 1553, -238481, 4553, 1254638551, -35872740703, -17157807788193, 1532562286297113, 488815558185860999, -101586398550375052879, -24471009470566855107377, 10960094402513781594777321 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..14.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tanh[Tan[Sin[x]]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Oct 24 2016 *)

CROSSREFS

Sequence in context: A012689 A098632 A192275 * A220991 A165388 A124126

Adjacent sequences:  A009804 A009805 A009806 * A009808 A009809 A009810

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Oct 24 2016

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 January 25 16:01 EST 2022. Contains 350572 sequences. (Running on oeis4.)