A009815 - OEIS

A009815

tanh(tan(x)*sin(x))=2/2!*x^2+4/4!*x^4-178/6!*x^6-5336/8!*x^8...

0, 2, 4, -178, -5336, 121082, 24994924, 661822982, -273928948016, -42186434881678, 4278599785289044, 2873614390992176702, 193732299468570630904, -268774878028807800675478, -95724942960306213127796036

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

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

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tanh[Tan[x]*Sin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 16 2016 *)

CROSSREFS

Sequence in context: A260900 A009553 A012371 * A012693 A018608 A018611

Adjacent sequences: A009812 A009813 A009814 * A009816 A009817 A009818

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program removed by Harvey P. Dale, Aug 16 2016

STATUS

approved