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A069853
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Numerators of coefficients of expansion of sinh(x)/sin(x) (even powers only).
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5
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1, 1, 1, 13, 17, 97, 1247, 4937, 6673, 1058467, 1380290071, 3216636877, 536799743, 8113510922983, 448402165451, 39917099698166381, 841245146920202183, 1449011221261558349, 5272145758556532286373, 59293985401199969565319, 11617394997961948860617
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OFFSET
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0,4
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LINKS
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EXAMPLE
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G.f. = 1 + (1/3)*x^2 + (1/18)*x^4 + (13/1890)*x^6 + (17/22680)*x^8 + (97/1247400)*x^10 + ...
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MAPLE
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a:= n-> numer(coeff(series(sinh(x)/sin(x), x, 2*n+2), x, 2*n)):
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MATHEMATICA
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With[{m=60}, CoefficientList[Series[Sinh[x]/Sin[x], {x, 0, m}], x]][[1 ;; ;; 2]]//Numerator (* G. C. Greubel, Jan 31 2022 *)
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PROG
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(Magma)
m:=60; R<x>:=PowerSeriesRing(Rationals(), m);
b:= Coefficients(R!( Sinh(x)/Sin(x) ));
[Numerator( b[2*n-1] ): n in [1..Floor((m-2)/2)]]; // G. C. Greubel, Jan 31 2022
(Sage) [numerator( ( sinh(x)/sin(x) ).series(x, 2*n+3).list()[2*n] ) for n in (0..60)] # G. C. Greubel, Jan 31 2022
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CROSSREFS
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KEYWORD
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easy,frac,nonn
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AUTHOR
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STATUS
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approved
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