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A013551 Numerator of [x^n] in the Taylor expansion exp(cot(x)-coth(x))= 1-2*x/3 +2x^2/9 -4*x^3/81 +2*x^4/243 -136*x^5/25515 +676*x^6/229635 -... 1
1, -2, 2, -4, 2, -136, 676, -656, 62, -47672, 2714132, -3091664, 7223932, -16788784, 120994136, -15764283616, 13831453742, -3729134588968, 463898158095404, -119174509180016 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The inner function is cot(x)-coth(x) = -2x/3 -4x^5/945 -4x^9/93555 -8x^13/18243225 -...

LINKS

Harvey P. Dale, Table of n, a(n) for n = 0..485

MATHEMATICA

Numerator[CoefficientList[Series[Exp[Cot[x]-Coth[x]], {x, 0, 20}], x] ] (* Harvey P. Dale, Feb 16 2014 *)

CROSSREFS

Sequence in context: A227509 A279094 A129243 * A252040 A084896 A011388

Adjacent sequences:  A013548 A013549 A013550 * A013552 A013553 A013554

KEYWORD

sign,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 23 21:46 EST 2017. Contains 295141 sequences.