A079575 Number of unlabeled, connected graphs on n vertices with no induced subgraph isomorphic to a bull-graph.

1, 1, 2, 6, 20, 93, 480, 2960, 19475, 140851, 1116717, 10329833, 121557264

Offset: 1

Author

Jim Nastos, Jan 24 2003

Keywords

• nonn
• more

Comments

A bull-graph is formed by adding a 5th vertex to a 4-path adjacent only to the middle two vertices on the path.

Links

• C. De Simone and A. Sassano, Stability number of bull- and chair-free graphs, Discrete Appl. Math. 41 (1993) 121-129.
• Travis Hoppe and Anna Petrone, Encyclopedia of Finite Graphs
• Falk Hüffner, tinygraph, software for generating integer sequences based on graph properties, version ece94ef.
• Eric Weisstein's World of Mathematics, Bull Graph

Crossrefs

Cf. A244427 (no bull subgraph).

Extensions

a(10)-a(13) added using tinygraph by Falk Hüffner, Jan 15 2016