A012728 sin(arctanh(x)*arctan(x))=2/2!*x^2+88/6!*x^6+112032/10!*x^10...

2, 88, 112032, 339519360, -45065746337280, -13641523340876605440, -5909672857101969499054080, -4213934311138261721595771125760

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: A053950 A266182 A362519 * A012733 A058459 A355272

Adjacent sequences: A012725 A012726 A012727 * A012729 A012730 A012731

Keyword

sign

Author

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

Status

approved