A345247 Number of unlabeled graphs of odd girth at least 7 with n vertices.

1, 2, 3, 7, 13, 35, 89, 306, 1141, 5615, 33397, 260624, 2623475, 35100394, 627244166, 15122214205, 493568138475

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 A371181 A293994

Adjacent sequences: A345244 A345245 A345246 * A345248 A345249 A345250

Keyword

nonn,hard,more

Author

Brendan McKay, Jun 12 2021

Status

approved