This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A006786 M1149 #51 Jul 08 2025 16:54:38 %S A006786 1,2,4,8,18,44,117,351,1230,5069,25181,152045,1116403,9899865, %T A006786 104980369,1318017549,19427531763,333964672216,6660282066936 %N A006786 Number of squarefree graphs on n vertices. %D A006786 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006786 CombOS - Combinatorial Object Server, <a href="http://combos.org/nauty">Generate graphs</a> %H A006786 Brendan McKay, <a href="/A006785/a006785.pdf">Emails to N. J. A. Sloane, 1991</a> %H A006786 B. D. McKay, <a href="http://users.cecs.anu.edu.au/~bdm/papers/orderly.pdf">Isomorph-free exhaustive generation</a>, J Algorithms, 26 (1998) 306-324. %H A006786 S. Uijlen, B. Westerbaan, <a href="http://arxiv.org/abs/1412.8544">A Kochen-Specker system has at least 22 vectors</a>, arXiv preprint arXiv:1412.8544 [cs.DM], 2014. %H A006786 S. Uijlen and B. Westerbaan, <a href="https://doi.org/10.1007/s00354-016-0202-5">A Kochen-Specker System Has at Least 22 Vectors</a>, New Generation Computing, Vol. 34, No. 1-2 (2016), 3-23. %H A006786 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Square-FreeGraph.html">Square-Free Graph</a> %H A006786 <a href="/index/Sq#square_free">Index entries for sequences of squarefree graphs</a> %Y A006786 Cf. A000088, A077269 (connected), A345249 (labeled), A039751 (complement). Row sums of A300756. %K A006786 nonn,more %O A006786 1,2 %A A006786 _N. J. A. Sloane_ %E A006786 2 more terms (from the McKay paper) from _Vladeta Jovovic_, May 17 2008 %E A006786 2 more terms from _Brendan McKay_, Mar 11 2018