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Search: id:A139621
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| A139621 |
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Table read by rows: T(n,k) is the number of connected directed multigraphs with loops and no vertex of degree 0, with n arcs and k vertices. |
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+0
5
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| 1, 1, 1, 4, 3, 1, 8, 15, 8, 1, 16
(list; graph; listen)
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OFFSET
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1,4
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COMMENT
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Length of the n^th row: n+1.
T(n,1) = 1, T(n,2) = T139654(n,2) - floor(n/2), T(n,n+1) = A022017(n).
Row sums: A139626.
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LINKS
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B. Jubin, Sequences contributed to the OEIS.
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CROSSREFS
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Cf. A136564, A139622.
Adjacent sequences: A139618 A139619 A139620 this_sequence A139622 A139623 A139624
Sequence in context: A038763 A128007 A098458 this_sequence A123160 A039758 A109692
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KEYWORD
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nonn
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AUTHOR
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Benoit Jubin (benoit_jubin(AT)yahoo.fr), May 01 2008
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