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%I #26 Mar 17 2020 04:31:59
%S 1,1,2,5,17,81,519,5218,81677,2014360,76140741,4303246908
%N Number of connected 3-colorable (i.e., chromatic number <= 3) simple graphs on n nodes.
%H Maria Chudnovsky, Jan Goedgebeur, Oliver Schaudt, Mingxian Zhong, <a href="http://arxiv.org/abs/1504.06979">Obstructions for three-coloring graphs without induced paths on six vertices</a>, arXiv preprint, arXiv:1504.06979 [math.CO], 2015-2018.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/n-ColorableGraph.html">n-Colorable Graph</a>
%F Inverse Euler transform of A076315. - _Andrew Howroyd_, Dec 02 2018
%t A076315 = Cases[Import["https://oeis.org/A076315/b076315.txt", "Table"], {_, _}][[All, 2]];
%t (* EulerInvTransform is defined in A022562 *)
%t EulerInvTransform[A076315] (* _Jean-François Alcover_, Sep 25 2019, updated Mar 17 2020 *)
%Y Cf. A005142, A076323, A076324, A076325, A076326, A076327, A076328.
%Y Cf. A076279, A076315, A084269, A126737.
%K nonn,more
%O 1,3
%A _Eric W. Weisstein_, Oct 06 2002
%E a(10)-a(11) from _Andrew Howroyd_, Dec 02 2018
%E a(12) from _Jinyuan Wang_, Feb 23 2020
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