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A049214
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Scaled coefficients of (arctanh x)^3.
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3
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1, 20, 784, 52352, 5360256, 782525952, 154594381824, 39746508226560, 12902483299368960, 5162443736924160000, 2496471943395999744000, 1435556519572510605312000, 968234590214616380866560000
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OFFSET
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0,2
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LINKS
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FORMULA
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E.g.f.: (arctanh x)^3 or (1-x^2)^-1 * (arctanh x)^2.
a(n) is coefficient of x^(2*n+3) in (arctanh x)^3, multiplied by (2*n+3)!/6.
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EXAMPLE
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(arctanh x)^3 = x^3 + x^5 + 14/15*x^7 + 818/945*x^9 + ...
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MATHEMATICA
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a[n_] := SeriesCoefficient[ArcTanh[x]^3, {x, 0, 2n+3}]*(2n+3)!/6;
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Joe Keane (jgk(AT)jgk.org)
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STATUS
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approved
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