A079566 Number of unlabeled, connected graphs on n vertices which have no induced subgraph isomorphic to a C4 (cycle on 4 vertices.)

1, 1, 2, 5, 16, 63, 313, 2014, 16724, 178608, 2422046, 41049952, 855470220

Offset

1,3

Comments

Different from A345673.

Links

Table of n, a(n) for n=1..13.

Z. Blázsik, M. Hujter, M. Pluhár and Z. Tuza, Graphs with no C4 and 2K2, Discrete Math. 115 (1993) 51-55.

Uli Fahrenberg, Christian Johansen, Georg Struth, Ratan Bahadur Thapa, Generating Posets Beyond N, arXiv:1910.06162 [cs.FL], 2019.

Uli Fahrenberg, Christian Johansen, Georg Struth, Krzysztof Ziemiański, Posets with Interfaces for Concurrent Kleene Algebra, arxiv:2106.10895 [cs.FL], 2021.

Crossrefs

Cf. A345673.

Sequence in context: A111004 A344640 A345673 * A059685 A000112 A205498

Adjacent sequences: A079563 A079564 A079565 * A079567 A079568 A079569

Keyword

more,nonn

Author

Jim Nastos, Jan 24 2003

Extensions

More terms from Falk Hüffner, Jan 11 2016, computed using https://github.com/falk-hueffner/tinygraph (nauty based) version 8489dde

Status

approved