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 A068917 Numerators of coefficients in 1/sin(x) - 1/sinh(x) power series. 9

%I #14 Nov 11 2016 10:27:50

%S 1,31,73,8191,5749691557,3324754717,22076500342261,

%T 925118910976041358111,8089941578146657681,21194489326041221593005331,

%U 3342730069684120811652882591487741,4204720064739945338027515648494601

%N Numerators of coefficients in 1/sin(x) - 1/sinh(x) power series.

%H G. C. Greubel, <a href="/A068917/b068917.txt">Table of n, a(n) for n = 1..125</a>

%F a(3k+1) = (4k+2)!, a(3k+2) = (4k+4)!, a(3k+3) = (4k+5)!/2.

%e cosec(x) - cosech(x) = x/3 + 31*x^5/7560 + 73*x^9/1710720 + 8191*x^13/18681062400 + ...

%t Select[Numerator[CoefficientList[Series[1/Sin[x] - 1/Sinh[x], {x, 0, 500}], x]], # != 0 &] (* _G. C. Greubel_, Nov 11 2016 *)

%Y Cf. A068918.

%K easy,frac,nonn

%O 1,2

%A _Benoit Cloitre_, Mar 29 2002

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Last modified April 21 08:26 EDT 2024. Contains 371850 sequences. (Running on oeis4.)