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A345247 Number of unlabeled graphs of odd girth at least 7 with n vertices. 1
1, 2, 3, 7, 13, 35, 89, 306, 1141, 5615, 33397, 260624, 2623475, 35100394, 627244166, 15122214205, 493568138475 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

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

LINKS

Table of n, a(n) for n=1..17.

CROSSREFS

EULER transform of A165452.

Sequence in context: A006840 A123408 A033995 * A013917 A293994 A196419

Adjacent sequences:  A345244 A345245 A345246 * A345248 A345249 A345250

KEYWORD

nonn,hard

AUTHOR

Brendan McKay, Jun 12 2021

STATUS

approved

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Last modified August 3 01:59 EDT 2021. Contains 346430 sequences. (Running on oeis4.)