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A012728 sin(arctanh(x)*arctan(x))=2/2!*x^2+88/6!*x^6+112032/10!*x^10... 0
2, 88, 112032, 339519360, -45065746337280, -13641523340876605440, -5909672857101969499054080, -4213934311138261721595771125760 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..7.

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Sin[ArcTanh[x]*ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {3, -1, 4}]] (* Ray Chandler, Nov 28 2016 *)

CROSSREFS

Sequence in context: A001904 A053950 A266182 * A012733 A058459 A105268

Adjacent sequences:  A012725 A012726 A012727 * A012729 A012730 A012731

KEYWORD

sign

AUTHOR

Patrick Demichel (patrick.demichel(AT)hp.com)

STATUS

approved

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Last modified December 12 22:06 EST 2019. Contains 329963 sequences. (Running on oeis4.)