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URL: https://oeis.org/A006786

⇱ A006786 - OEIS

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A006786
Number of squarefree graphs on n vertices.
9
1, 2, 4, 8, 18, 44, 117, 351, 1230, 5069, 25181, 152045, 1116403, 9899865, 104980369, 1318017549, 19427531763, 333964672216, 6660282066936
OFFSET
1,2
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
CombOS - Combinatorial Object Server, Generate graphs
B. D. McKay, Isomorph-free exhaustive generation, J Algorithms, 26 (1998) 306-324.
S. Uijlen, B. Westerbaan, A Kochen-Specker system has at least 22 vectors, arXiv preprint arXiv:1412.8544 [cs.DM], 2014.
S. Uijlen and B. Westerbaan, A Kochen-Specker System Has at Least 22 Vectors, New Generation Computing, Vol. 34, No. 1-2 (2016), 3-23.
Eric Weisstein's World of Mathematics, Square-Free Graph
CROSSREFS
Cf. A000088, A077269 (connected), A345249 (labeled), A039751 (complement). Row sums of A300756.
Sequence in context: A100132 A176720 A088457 * A125809 A245176 A000117
KEYWORD
nonn,more
EXTENSIONS
2 more terms (from the McKay paper) from Vladeta Jovovic, May 17 2008
2 more terms from Brendan McKay, Mar 11 2018
STATUS
approved