A102076 Numerators of e.g.f. cosec(arctanh(x)).

-1, -1, 125, 5585, 146835, 199553825, 16151898425, 3951808537625, 54159749674008875, 7187045526725631125, 4971794789793419144375, 836133262846273312334375, 125448452657856727433328125

Offset

1,3

Links

Table of n, a(n) for n=1..13.

Example

cosec(arctanh(x)) = 1/x - x/6 - 1/12*x^3/3! + 125/126x^5/5! +...
cosech(arctan(x)) = 1/x + x/6 - 1/12*x^3/3! - 125/126x^5/5! +...

Mathematica

With[{nn=30}, Take[Numerator[CoefficientList[Series[Csc[ArcTanh[x]], {x, 0, nn}], x] Range[0, nn-1]!], {2, -1, 2}]]//Quiet (* Harvey P. Dale, Aug 01 2021 *)

Crossrefs

Denominators are in A102077.

Sequence in context: A265477 A017583 A046232 * A223229 A030695 A317981

Adjacent sequences: A102073 A102074 A102075 * A102077 A102078 A102079

Keyword

sign,frac

Author

Ralf Stephan, Dec 31 2004

Status

approved