A326215 - OEIS

A326215

Number of Hamiltonian unlabeled n-vertex graphs with loops.

0, 2, 0, 4, 20

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

A graph is Hamiltonian if it contains a cycle passing through every vertex exactly once.

LINKS

EXAMPLE

Non-isomorphic representatives of the a(3) = 4 edge-sets:

{12,13,23}

{12,13,23,33}

{12,13,22,23,33}

{11,12,13,22,23,33}

CROSSREFS

The labeled case is A326240.

The directed case is A326226 (with loops) or A326225 (without loops).

The case without loops A003216.

KEYWORD

nonn,more

AUTHOR

Gus Wiseman, Jun 17 2019

STATUS

approved