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A009717 Expansion of tan(tanh(x))*sin(x). 1
0, 2, -4, -42, 1336, -16726, -1194700, 153304830, -10698400400, 188012481362, 107922523124588, -26275693823306202, 3726087789656495272, -203071274271083537926, -64313415452872137435484 (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[Tan[Tanh[x]]*Sin[x], {x, 0, nn}], x] Range[ 0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jun 14 2019 *)

CROSSREFS

Sequence in context: A215921 A009811 A009591 * A018317 A059794 A116611

Adjacent sequences:  A009714 A009715 A009716 * A009718 A009719 A009720

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Jun 14 2019

STATUS

approved

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Last modified April 10 16:16 EDT 2021. Contains 342845 sequences. (Running on oeis4.)