A372174 Number of unlabeled simple graphs covering n vertices with a unique triangle.

0, 0, 0, 1, 1, 5, 16, 79, 424, 3098, 28616

Offset: 0

Author

Gus Wiseman, Apr 24 2024

Keywords

• nonn
• more

Comments

The labeled version is A372171.

Links

• Gus Wiseman, The a(3) = 1 through a(6) = 16 covering graphs with a unique triangle.

Crossrefs

The non-covering version is column k = 1 of A263340, labeled A372170.

Case of A370167 with a unique triangle, labeled A054548.

For no triangles we have A372169, labeled A372168 (non-covering A213434).

The labeled version is A372171, column k = 1 of A372167.

Column k = 1 of A372173, labeled A372167.

For cycles (not just triangles) we have A372191, labeled A372195.

The non-covering version is A372194, labeled A372172.

A000088 counts unlabeled graphs, labeled A006125.

A001858 counts acyclic graphs, unlabeled A005195.

A002494 counts unlabeled covering graphs, labeled A006129.

A372176 counts labeled graphs by directed cycles, covering A372175.

Cf. A000055, A053530, A137917, A137918, A140637, A144958, A370169.

Formula

First differences of A372194.