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 A076323 Number of connected 4-colorable (i.e., chromatic number <= 4) simple graphs on n nodes. 7
 1, 1, 2, 6, 20, 107, 801, 10227, 231228, 9708788, 743177051 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Maria Chudnovsky, Jan Goedgebeur, Oliver Schaudt, Mingxian Zhong, Obstructions for three-coloring graphs without induced paths on six vertices, arXiv preprint, arXiv:1504.06979 [math.CO], 2015-2018. Eric Weisstein's World of Mathematics, n-Colorable Graph FORMULA Inverse Euler transform of A076316. - Andrew Howroyd, Dec 02 2018 MATHEMATICA A076316 = Cases[Import["https://oeis.org/A076316/b076316.txt", "Table"], {_, _}][[All, 2]]; (* EulerInvTransform is defined in A022562 *) EulerInvTransform[A076316] (* Jean-François Alcover, Sep 25 2019, updated Mar 17 2020 *) CROSSREFS Cf. A005142, A076322, A076324, A076325, A076326, A076327, A076328. Cf. A076280, A076316, A084269, A126738. Sequence in context: A079455 A052433 A078566 * A241782 A268562 A287009 Adjacent sequences:  A076320 A076321 A076322 * A076324 A076325 A076326 KEYWORD nonn,more AUTHOR Eric W. Weisstein, Oct 06 2002 EXTENSIONS a(10)-a(11) from Andrew Howroyd, Dec 02 2018 STATUS approved

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Last modified May 12 10:12 EDT 2021. Contains 343821 sequences. (Running on oeis4.)