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A191646 Triangle read by rows: T(n,k) = number of connected multigraphs with n>=0 edges and 1<=k<=n+1 vertices, with no loops allowed. 5
1, 0, 1, 0, 1, 1, 0, 1, 2, 2, 0, 1, 3, 5, 3, 0, 1, 4, 11, 11, 6, 0, 1, 6, 22, 34, 29, 11, 0, 1, 7, 37, 85, 110, 70, 23, 0, 1, 9, 61, 193, 348, 339, 185, 47, 0, 1, 11, 95, 396, 969, 1318, 1067, 479, 106, 0, 1, 13, 141, 771, 2445, 4457, 4940, 3294, 1279, 235 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,9

LINKS

R. J. Mathar, Table of n, a(n) for n = 0..119

R. J. Mathar, Statistics on Small Graphs, arXiv:1709.09000 (2017), Section 4.

Gordon Royle, Small Multigraphs

Numbers in this table were computed using nauty 2.4

EXAMPLE

Triangle begins:

1;

0,1;

0,1,1;

0,1,2,2;

0,1,3,5,3;

0,1,4,11,11,6;

0,1,6,22,34,29,11;

...

CROSSREFS

Cf. A054923, A192517, A253186 (column k=3), A290778 (column k=4).

Row sums give A076864.

Sequence in context: A296068 A144064 A172236 * A297321 A277938 A130020

Adjacent sequences:  A191643 A191644 A191645 * A191647 A191648 A191649

KEYWORD

nonn,tabl

AUTHOR

Alberto Tacchella, Jul 04 2011

STATUS

approved

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Last modified February 20 00:51 EST 2018. Contains 299357 sequences. (Running on oeis4.)