A013553 Numerator of [x^(2n+1)] of the Taylor expansion -arcsin(cot(x)-coth(x)).

2, 4, 8, 272, 15640, 103504, 203248, 4712878048, 994787896, 29947918028368, 19403266491914896, 44494589501437664, 1343012003853467792, 940284256279455687458272, 18264529537961367195872, 13625209118796335138813851456

Offset

0,1

Links

G. C. Greubel, Table of n, a(n) for n = 0..200

Example

2*x/3 +4*x^3/81 +8*x^5/567 +272*x^7/76545 +15640*x^9/13640319 +...

Mathematica

Numerator[Take[CoefficientList[Series[-ArcSin[Cot[x] - Coth[x]], {x, 0, 26}], x], {2, -1, 2}]] (* G. C. Greubel, Nov 13 2016 *)

Crossrefs

Sequence in context: A033555 A130134 A082613 * A302864 A061089 A067499

Adjacent sequences: A013550 A013551 A013552 * A013554 A013555 A013556

Keyword

nonn,frac

Author

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

Extensions

Name edited by R. J. Mathar, Dec 21 2011

Status

approved