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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

Table of n, a(n) for n=1..15.

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

Adjacent sequences:  A079574 A079575 A079576 * A079578 A079579 A079580

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 November 20 05:07 EST 2019. Contains 329323 sequences. (Running on oeis4.)