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Search: id:A062735
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| A062735 |
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Triangular array T(n,k) giving number of weakly connected digraphs with n labeled nodes and k arcs (n >= 1, 0 <= k <= n(n-1)). |
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1
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| 1, 0, 2, 1, 0, 0, 12, 20, 15, 6, 1, 0, 0, 0, 128, 432, 768, 920, 792, 495, 220, 66, 12, 1, 0, 0, 0, 0, 2000, 11104, 33880, 73480, 123485, 166860, 184426, 167900, 125965, 77520, 38760, 15504, 4845, 1140, 190, 20, 1, 0, 0, 0, 0, 0, 41472, 337920, 1536000, 5062080
(list; table; graph; listen)
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OFFSET
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1,3
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FORMULA
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E.g.f.: 1+log( Sum_{n >= 0, k >= 0} binomial(n*(n-1), k)*x^n/n!*y^k ).
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EXAMPLE
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[1], [0, 2, 1], [0, 0, 12, 20, 15, 6, 1], [0, 0, 0, 128, 432, 768, 920, 792, 495, 220, 66, 12, 1], ...
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CROSSREFS
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Cf. (row sums) A003027, (unlabeled case) A054733.
Sequence in context: A057274 A088632 A057272 this_sequence A054547 A025439 A116852
Adjacent sequences: A062732 A062733 A062734 this_sequence A062736 A062737 A062738
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KEYWORD
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easy,nonn,tabl
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AUTHOR
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Vladeta Jovovic (vladeta(AT)eunet.rs), Jul 12 2001
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