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A013541 Numerator of the coefficient [x^(2n)] of the Taylor series cos(cosec(x) - coth(x)). 2

%I

%S 1,-1,217,-214279,824071,-337533513773,8320611986431,

%T -2303253020856673,7111553692366818727,-4825610634542923917792887,

%U 6031202702741413913839327,-1707209475196496091030335944673

%N Numerator of the coefficient [x^(2n)] of the Taylor series cos(cosec(x) - coth(x)).

%C Most (but not all) denominators are in the bisection of A202382.

%H G. C. Greubel, <a href="/A013541/b013541.txt">Table of n, a(n) for n = 0..194</a>

%e 1 - x^2/72 + 217*x^4/31104 - 214279*x^6/235146240 + 824071*x^8/9674588160 - ...

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

%K sign,frac

%O 0,3

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

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

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Last modified January 23 15:33 EST 2022. Contains 350514 sequences. (Running on oeis4.)