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A013539 Numerator of the coefficient [x^(2n+1)] of the Taylor series tan(cosec(x)-coth(x)). 1
-1, 13, 877, 2675, 8260913, 410433607, 223758294041, 27276568423051, 127639993821278611, 10512596641186789291, 8302408982767874894797, 3077103479886222660379217 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

EXAMPLE

-x/6 + 13*x^3/324 + 877*x^5/816480 + 2675*x^7/17635968 + ...

MATHEMATICA

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

CROSSREFS

Sequence in context: A331341 A123838 A294793 * A201255 A196695 A196728

Adjacent sequences:  A013536 A013537 A013538 * A013540 A013541 A013542

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 December 7 12:17 EST 2021. Contains 349581 sequences. (Running on oeis4.)