A366220 Number of unlabeled graphs on n vertices without 4-cycles or 5-cycles.

1, 2, 4, 8, 17, 41, 100, 267, 772, 2442, 8512, 33076, 143430, 697037, 3791763, 23043296, 155896190, 1169641637, 9693805936

Offset

1,2

Comments

Disconnected graphs are included.

Links

Table of n, a(n) for n=1..19.

Crossrefs

Cf. A366223 (biconnected graphs in the same class).

Sequence in context: A332398 A307555 A104879 * A331686 A156805 A200542

Adjacent sequences: A366217 A366218 A366219 * A366221 A366222 A366223

Keyword

nonn,hard,more

Author

Brendan McKay, Oct 04 2023

Status

approved