A241784 Number of simple connected graphs on n nodes with no cycle of length 5.

1, 1, 2, 6, 13, 44, 144, 577, 2457, 12499, 72394, 508942, 4408389, 49858593, 769196039, 16729819397

Offset

1,3

Comments

Inverse EULER transformation of A345216 (not necessarily connected)

Links

Table of n, a(n) for n=1..16.

Travis Hoppe and Anna Petrone, Encyclopedia of Finite Graphs

T. Hoppe and A. Petrone, Integer sequence discovery from small graphs, arXiv preprint arXiv:1408.3644 [math.CO], 2014.

F. Hüffner, tinygraph, software for generating integer sequences based on graph properties, version 29e68fa.

Eric Weisstein's World of Mathematics, Cycle Graph

Crossrefs

Cf. Squarefree (C_4) graphs A077269.

Sequence in context: A001373 A320804 A284223 * A211995 A245010 A057243

Adjacent sequences: A241781 A241782 A241783 * A241785 A241786 A241787

Keyword

nonn,hard,more

Author

Travis Hoppe and Anna Petrone, Apr 28 2014

Extensions

a(11)-a(14) added using tinygraph by Falk Hüffner, Sep 22 2020

a(15) and a(16) added by Brendan McKay, Jun 10 2021

Status

approved