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A064074
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Generalized tangent number d(9,n).
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4
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12, 2160, 1415232, 1951153920, 4611775398912, 16653520425185280, 85285640517460180992, 587950108643300554506240, 5249943672359370392053481472, 58942155612887708094647422156800, 812681867463337890406273965833060352, 13499458606943117379769406368204676136960
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = (2*n-1)!*[x^(2*n-1)](sec(9*x)*4*sin(3*x)*cos(3*x)^2). - Peter Luschny, Nov 21 2021
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MAPLE
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egf := sec(9*x)*4*sin(3*x)*cos(3*x)^2: ser := series(egf, x, 24):
seq((2*n-1)!*coeff(ser, x, 2*n-1), n = 1..10); # Peter Luschny, Nov 21 2021
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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