

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
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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



