%I #14 Nov 12 2016 18:08:33
%S 1,1,1,1,19,25031,18421,622177,283401163,24826632949,2243454779,
%T 4882905709651,43798187793808543,46704901267812186793,
%U 5325187532598955153807
%N Numerator of [x^(2n)] of the Taylor series sech(cosec(x)cot(x)) = 1 x^2/8 x^4/128 +x^6/15360 +19*x^8/294912 +25031*x^10/3715891200+... .
%C The e.g.f. related to x/2, sech(cosec(x)cot(x)) = 1 1*x^2/(2^2*2!) 3*x^4*(2^4*4!) +3*x^6/(2^6*6!) +665*x^8/(2^8*8!) +.. is (up to signs) apparently provided by A009011.
%H G. C. Greubel, <a href="/A013528/b013528.txt">Table of n, a(n) for n = 0..200</a>
%t Numerator[Take[CoefficientList[Series[Sech[Csc[x]  Cot[x]], {x,0,50}], x], {1, 1, 2}]] (* _G. C. Greubel_, Nov 12 2016 *)
%K sign,frac
%O 0,5
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E Name edited by _R. J. Mathar_, Dec 20 2011
