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A292748
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Number of 4-good trees with n nodes.
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2
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1, 1, 2, 6, 25, 140, 1015, 9065, 95095, 1131900, 14964950, 217091875, 3430276850, 58734600925, 1084950741875, 21527855724375, 456878274102250, 10327751636452250, 247707850627612375, 6281906665784750000, 167928158962254315625, 4719079778905601484375
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OFFSET
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0,3
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LINKS
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FORMULA
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Coefficients of (x-1) in series reversion of 1+x+x^2/2!+x^3/3!+x^4/4! multiplied by (-1)^(n+1)*n!. - Benedict W. J. Irwin, Aug 16 2019
E.g.f.: A'(x) where A(x) is the series reversion of x - x^2/2 + x^3/6 - x^4/24. - Andrew Howroyd, Aug 24 2019
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MATHEMATICA
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m = 23;
egf = D[InverseSeries[x - x^2/2 + x^3/6 - x^4/24 + O[x]^m], x];
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PROG
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(PARI) Vec(serlaplace(serreverse(-sum(k=1, 4, (-1)^k*x^k/k!) + O(x^30)))) \\ Andrew Howroyd, Aug 24 2019
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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