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Search: id:A082402
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| A082402 |
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Number of n-node labeled weakly connected acyclic digraphs. |
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+0
3
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| 0, 1, 2, 18, 446, 26430, 3596762, 1111506858, 774460794326, 1206342801843750, 4162927142993589122, 31557464707483035620178, 521560130632321900618457246, 18669813048017298278379855511470
(list; graph; listen)
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OFFSET
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0,3
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REFERENCES
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R. W. Robinson, Counting labeled acyclic digraphs, pp. 263-264 of F. Harary, editor, New Directions in the Theory of Graphs. Academic Press, NY, 1973.
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FORMULA
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E.g.f.: ln(B(x)) where B(x) is e.g.f. for A003024. a(n) = A003024(n) - Sum_{k=1..n-1} binomial(n-1, k-1)*a(k)*A003024(n-k).
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CROSSREFS
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Cf. A003024.
Sequence in context: A090307 A123311 A132911 this_sequence A053916 A015203 A121936
Adjacent sequences: A082399 A082400 A082401 this_sequence A082403 A082404 A082405
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KEYWORD
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nonn
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AUTHOR
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Vladeta Jovovic (vladeta(AT)Eunet.yu), Apr 15 2003
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