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A079577 Number of unlabeled, connected graphs on n vertices that have no induced subgraph isomorphic to a bull, a P5 or a P5-bar. 1
1, 1, 2, 6, 18, 67, 248, 1005, 4068, 16955, 71090, 302194, 1294752, 5598368, 24382450 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Bull = 4-path with a 5th vertex adjacent to the two middle vertices of the path P5 = path on 5 vertices P5-bar = complement of a P5
LINKS
J. L. Fouquet, A Decomposition for a class of (P5,P5-bar)-free graphs, Discrete Math. 121 (1993) 75-83.
F. Hüffner, tinygraph, software for generating integer sequences based on graph properties, version 6e0a59d.
EXAMPLE
O.........O
|.........|
.\......./
..O-----O bull
...\.../
....\./
.....O
CROSSREFS
Cf. A267602 (with additional "prime" requirement)
Sequence in context: A173385 A057693 A053496 * A150078 A150079 A150080
KEYWORD
more,nonn
AUTHOR
Jim Nastos, Jan 24 2003
EXTENSIONS
a(10)-a(15) added using tinygraph by Falk Hüffner, Jan 15 2016
Definition corrected ("are prime" omitted) by Falk Hüffner, Jan 18 2016
STATUS
approved

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Last modified May 26 16:43 EDT 2024. Contains 372840 sequences. (Running on oeis4.)