OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..200
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
KEYWORD
sign,frac
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Name edited by R. J. Mathar, Dec 20 2011
STATUS
approved