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A013533 Numerator of [x^(2n+1)] in the Taylor expansion arctan(cosec(x) - cosech(x)). 1
1, -1, 67, -319, 172747, -5036627, 12689179, -142848518639, 9522619510673, -15014600586761717, 98523462918652219853, -281638034717631160979, 20971906033995645898061, -1307646596002305911998781633 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
EXAMPLE
x/3 - x^3/81 + 67*x^5/13608 - 319*x^7/612360 + 172747*x^9/1745960832 - ...
MATHEMATICA
Numerator[Take[CoefficientList[Series[ArcTan[Csc[x] - Csch[x]], {x, 0, 25}], x], {2, -1, 2}]] (* G. C. Greubel, Nov 12 2016 *)
CROSSREFS
Cf. A068917.
Sequence in context: A270615 A142804 A033242 * A012865 A026911 A142371
KEYWORD
sign,frac
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Name edited by R. J. Mathar, Dec 20 2011
STATUS
approved

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Last modified May 27 12:27 EDT 2024. Contains 372858 sequences. (Running on oeis4.)