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A013553 Numerator of [x^(2n+1)] of the Taylor expansion -arcsin(cot(x)-coth(x)). 1
2, 4, 8, 272, 15640, 103504, 203248, 4712878048, 994787896, 29947918028368, 19403266491914896, 44494589501437664, 1343012003853467792, 940284256279455687458272, 18264529537961367195872, 13625209118796335138813851456 (list; graph; refs; listen; history; text; internal format)
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

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Last modified November 28 22:51 EST 2022. Contains 358421 sequences. (Running on oeis4.)