A013544 - OEIS

%I #14 Nov 13 2016 14:42:41

%S -1,7,-1013,64763,-3009173,5341411709,-857007547621,28828641126011,

%T -1030088087041163819,108508429719458111069,

%U -2005462402042629244533103,41348510060126079043949299,-132583025047910486114666220223

%N Numerator of the coefficient [x^(2n+1)] of tanh(cosec(x)-coth(x)).

%H G. C. Greubel, <a href="/A013544/b013544.txt">Table of n, a(n) for n = 0..200</a>

%e -x/6 +7*x^3/162 -1013*x^5/816480 +64763*x^7/88179840 -...

%t Numerator[Take[CoefficientList[Series[Tanh[Csc[x] - Coth[x]], {x,0,26}], x], {2, -1, 2}]] (* _G. C. Greubel_, Nov 13 2016 *)

%K sign,frac

%O 0,2

%A Patrick Demichel (patrick.demichel(AT)hp.com)

%E Name edited by _R. J. Mathar_, Dec 21 2011