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%I #20 Nov 13 2016 06:58:45
%S 1,1,5,5449,6973,518819753,1489058191,293416964947,2531578641757,
%T 8778884852410565513,2503198198587351877067,2378459715706347981795671,
%U 2343990771779851025499037,521048260968673067986908628597,35145358095152621756454620279473
%N Numerator of the coefficient [x^(2n)] in the Taylor series sec(cosec(x) - cosech(x)).
%H G. C. Greubel, <a href="/A013535/b013535.txt">Table of n, a(n) for n = 0..200</a>
%e 1 - x^2/18 + x^4/1944 - 5029*x^6/3674160 + 6697*x^8/264539520 - ...
%t Numerator[Take[CoefficientList[Series[Sec[Csc[x] - Csch[x]], {x,0,25}], x], {1, -1, 2}]] (* _G. C. Greubel_, Nov 12 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