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A013522 Numerator of [x^(2n+1)] in the Taylor expansion sinh(cosec(x)-cotan(x))= x/2 +x^3/16 +37*x^5/3840 +137*x^7/92160 +41641*x^9/185794560 + 3887*x^11/117964800 +... 1
1, 1, 37, 137, 41641, 3887, 241586893, 5721418891, 4315903789009, 2832484672207, 183184249105857781, 2154299222076719401, 1431144441595717024523, 386845480523042818420133 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Apparently a bisection of A047691.

The numerators in the e.g.f. of x/2, sinh(cosec(x)-cotan(x)) = x/(2^1*1!) +3*x^3/(2^3*3!) +37*x^5/(2^5*5!) +959*x^7/(2^7*7!) +41641*x^9/(2^9*9!)+.. are apparently covered by the absolute values of A003717.

LINKS

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

MATHEMATICA

Take[CoefficientList[Series[Sinh[Csc[x] - Cot[x]], {x, 0, 45}], x], {2, -1, 2}]] (* G. C. Greubel, Nov 12 2016 *)

CROSSREFS

Sequence in context: A044750 A141936 A244768 * A142498 A158591 A262318

Adjacent sequences:  A013519 A013520 A013521 * A013523 A013524 A013525

KEYWORD

nonn,frac

AUTHOR

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

EXTENSIONS

Name edited by R. J. Mathar, Dec 19 2011

STATUS

approved

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Last modified March 22 22:17 EDT 2017. Contains 283901 sequences.