A333163 Number of cubic graphs on n unlabeled nodes with half-edges.

1, 0, 0, 1, 3, 4, 12, 24, 70, 172, 525, 1530, 5078, 16994, 61456, 228898, 895910, 3617148, 15130833, 65084088, 287828488, 1304327221, 6050218591, 28675928883, 138730847262, 684300453848, 3438439910436, 17585597712632, 91479580896616, 483699938173293, 2598090378779507

Offset: 0

Author

Andrew Howroyd, Mar 11 2020

Keywords

• nonn

Comments

A half-edge is like a loop except it only adds 1 to the degree of its vertex.

a(n) is the number of simple graphs on n unlabeled nodes with every node having degree 2 or 3.

Crossrefs

Column k=3 of A333161.

Cf. A005638, A110040, A186417.