A079576 Number of unlabeled, connected graphs on n vertices that have no induced subgraph isomorphic to a gem, where a gem is a 4-path with a fifth vertex adjacent to all four of the vertices in the path.

1, 1, 2, 6, 20, 93, 534, 4291, 47120, 739310, 16641941, 539386425

Offset

1,3

References

A. Brandstadt and D. Kratsch, "On (P5,Gem)-free and (P5,Gem,co-Gem)-free Graphs: Structure and algorithmic applications," Manuscript 2000.

Links

Table of n, a(n) for n=1..12.

Qingqiong Cai, Jan Goedgebeur, and Shenwei Huang, Some Results on k-Critical P_5-Free Graphs, arXiv:2108.05492 [math.CO], 2021.

F. Hüffner, tinygraph, software for generating integer sequences based on graph properties, version e8699da.

Crossrefs

Sequence in context: A210690 A079575 A078564 * A079570 A131842 A348104

Adjacent sequences: A079573 A079574 A079575 * A079577 A079578 A079579

Keyword

more,nonn

Author

Jim Nastos, Jan 24 2003

Extensions

a(10)-a(12) added using tinygraph by Falk Hüffner, Jan 17 2016

Status

approved