Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #14 Nov 11 2016 21:25:03
%S 1,1,5,19,13793,7487,235549,4400752781,1455564577,75143281206379,
%T 17910727755514921,208450205999558953,8864292850179951461,
%U 36884532202496983982602507
%N Numerator of [x^(2n+1)] in the Taylor expansion arcsin(cosec(x) - cosech(x)) = x/3 + x^3/162 + 5*x^5/1134 + 19*x^7/76545 + 13793*x^9/218245104 + ...
%H G. C. Greubel, <a href="/A013531/b013531.txt">Table of n, a(n) for n = 0..235</a>
%t Select[Numerator[CoefficientList[Series[ArcSin[1/Sin[x] - 1/Sinh[x]], {x, 0, 52}], x]], # != 0 &] (* _G. C. Greubel_, Nov 11 2016 *)
%Y Cf. A068917.
%K nonn,frac
%O 0,3
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E Name edited by _R. J. Mathar_, Dec 20 2011