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A053454
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Number of weakly connected digraphs with n arcs.
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5
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1, 1, 4, 12, 53, 237, 1306, 7537, 47913, 322253, 2297874, 17191216, 134505656, 1095715055, 9267223594, 81162609328, 734511656413, 6856030049629, 65899370570285, 651338242941020, 6611459646337423, 68842439737228261
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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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PROG
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(PARI) \\ See A054733 for G, InvEulerMTS.
seq(n)=Vec(subst(Pol(InvEulerMTS(sum(i=0, n, G(i, y+O(y^n))*x^i, O(x*x^n)))), x, 1)) \\ Andrew Howroyd, Jan 28 2022
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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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