

A165452


Number of connected graphs of odd girth at least 7 with n vertices.


1



1, 1, 1, 3, 5, 17, 45, 184, 748, 4143, 26532, 221032, 2326853, 32202266, 589436301, 14459238676, 477812658943
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OFFSET

1,4


COMMENTS

The odd girth of a graph is the length of a shortest cycle of odd length. Thus, these are the connected graphs that do not have a triangle or C_5 as induced subgraph.  Falk Hüffner, Jan 15 2016
The bipartite graphs (which have no odd cycles) are included.


LINKS

Table of n, a(n) for n=1..17.
F. Hüffner, tinygraph, software for generating integer sequences based on graph properties, version ece94ef.


CROSSREFS

Cf. A005142, A024607.
Inverse EULER transform of A345247.
Sequence in context: A236458 A131342 A005142 * A106063 A215106 A006483
Adjacent sequences: A165449 A165450 A165451 * A165453 A165454 A165455


KEYWORD

nonn


AUTHOR

Friedrich Regen (friedrich.regen(AT)tuilmenau.de), Sep 20 2009


EXTENSIONS

a(15) and a(16) added using tinygraph by Falk Hüffner, Jan 15 2016
a(17) added by Brendan McKay, Jun 12 2021


STATUS

approved



