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A013522 Numerator of [x^(2n+1)] in the Taylor expansion sinh(cosec(x)-cotan(x))= x/2 +x^3/16 +37*x^5/3840 +137*x^7/92160 +41641*x^9/185794560 + 3887*x^11/117964800 +... 1

%I #13 Nov 12 2016 08:08:31

%S 1,1,37,137,41641,3887,241586893,5721418891,4315903789009,

%T 2832484672207,183184249105857781,2154299222076719401,

%U 1431144441595717024523,386845480523042818420133

%N Numerator of [x^(2n+1)] in the Taylor expansion sinh(cosec(x)-cotan(x))= x/2 +x^3/16 +37*x^5/3840 +137*x^7/92160 +41641*x^9/185794560 + 3887*x^11/117964800 +...

%C Apparently a bisection of A047691.

%C The numerators in the e.g.f. of x/2, sinh(cosec(x)-cotan(x)) = x/(2^1*1!) +3*x^3/(2^3*3!) +37*x^5/(2^5*5!) +959*x^7/(2^7*7!) +41641*x^9/(2^9*9!)+.. are apparently covered by the absolute values of A003717.

%H G. C. Greubel, <a href="/A013522/b013522.txt">Table of n, a(n) for n = 0..200</a>

%t Take[CoefficientList[Series[Sinh[Csc[x] - Cot[x]], {x,0,45}], x], {2, -1, 2}]] (* _G. C. Greubel_, Nov 12 2016 *)

%K nonn,frac

%O 0,3

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

%E Name edited by _R. J. Mathar_, Dec 19 2011

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Last modified April 24 14:18 EDT 2024. Contains 371960 sequences. (Running on oeis4.)