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A012190
tanh(arctan(sin(x)))=x-5/3!*x^3+121/5!*x^5-6845/7!*x^7+690481/9!*x^9...
0
1, -5, 121, -6845, 690481, -108594485, 24502918441, -7495966306925, 2984112329052001, -1498441322462840165, 926096248873419539161, -690670275602276172370205, 611502034169544516212107921
OFFSET
0,2
EXAMPLE
E.g.f.: tanh(arctan(sin(x))), even terms only. [From Harvey P. Dale, Sep 19 2011]
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Tanh[ArcTan[Sin[x]]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Sep 19 2011 *)
CROSSREFS
Sequence in context: A179299 A012179 A012026 * A012077 A012046 A012151
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved