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A128240
Number of n-node (unlabeled) connected graphs with girth 3.
5
0, 0, 1, 3, 15, 93, 794, 10850, 259700, 11706739, 1006609723, 164058686415, 50335888444167, 29003487017067011, 31397381129017616776, 63969560112658419275907, 245871831682052901418048916
OFFSET
1,4
COMMENTS
Number of unlabeled, connected graphs on n vertices with at least one induced subgraph isomorphic to a K_3, where K_3 is the complete graph on three vertices (a triangle). - Travis Hoppe and Anna Petrone, Jun 01 2014
LINKS
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
Eric Weisstein's World of Mathematics, Triangle-Free Graph
CROSSREFS
a(n) = A001349(n) - A024607(n).
Sequence in context: A308457 A241711 A243245 * A369270 A369301 A368964
KEYWORD
nonn
AUTHOR
Keith Briggs, May 05 2007
EXTENSIONS
Corrected and extended by Martin Fuller, May 01 2015
Information added by Falk Hüffner, Nov 27 2015
STATUS
approved