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A136564
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Array read by rows: T(n,k) is the number of directed multigraphs with loops with n arcs, k vertices and no vertex of degree 0.
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6
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1, 1, 1, 5, 4, 1, 1, 9, 21, 16, 4, 1, 1, 18, 71, 108, 71, 22, 4, 1, 1, 27, 194, 491, 557, 326, 101, 22, 4, 1, 1, 43, 476, 1903, 3353, 3062, 1587, 497, 111, 22, 4, 1, 1, 59, 1030, 6298, 16644, 22352, 17035, 7982, 2433, 555, 111, 22, 4, 1, 1, 84, 2095, 18823, 72064
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| Length of the n^th row: 2n.
T(n,1)=T(n,2n)=1 and T(n,2n-1)=4 if n>1.
Row sums: A052171.
Sums of the first 2 entries of each row: A005993.
Sums of the first 3 entries of each row: A050927.
Sums of the first 4 entries of each row: A050929.
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CROSSREFS
| Sequence in context: A132707 A046575 A154739 * A136042 A166044 A190287
Adjacent sequences: A136561 A136562 A136563 * A136565 A136566 A136567
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KEYWORD
| nonn,tabl
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AUTHOR
| Benoit Jubin (benoit_jubin(AT)yahoo.fr), Apr 14 2008
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EXTENSIONS
| More terms from Benoit Jubin and Vladeta Jovovic (vladeta(AT)eunet.yu), Sep 08 2008
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