A362908 Number of graphs on n unlabeled nodes with treewidth 2.

0, 0, 0, 1, 4, 17, 72, 323, 1639, 9203

Offset: 0

Author

Martin Rubey, May 09 2023

Keywords

• nonn
• more

Examples

			There is a single graph of treewidth 2 on 3 vertices, which is the complete graph.
		

Links

• Wikipedia, Treewidth.

Crossrefs

Column 2 of A263294.

Programs

SageMath

[sum(1 for g in graphs(n) if g.treewidth() == 2) for n in range(9)]