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A362908
Number of graphs on n unlabeled nodes with treewidth 2.
1
0, 0, 0, 1, 4, 17, 72, 323, 1639, 9203
OFFSET
0,5
EXAMPLE
There is a single graph of treewidth 2 on 3 vertices, which is the complete graph.
PROG
(SageMath) [sum(1 for g in graphs(n) if g.treewidth() == 2) for n in range(9)]
CROSSREFS
Column 2 of A263294.
Sequence in context: A122451 A257388 A113442 * A085732 A289159 A083330
KEYWORD
nonn,more
AUTHOR
Martin Rubey, May 09 2023
STATUS
approved