A198634 - OEIS

%I #68 Jan 03 2023 16:12:16

%S 1,2,4,11,33,152,1006,11805,257542,11011758,917095022,145164791300

%N Number of weakly perfect graphs on n nodes.

%C A graph is weakly perfect if it has equal chromatic and clique numbers.

%C First differs from A287007 (fractional chromatic number equals chromatic number) at a(8). - _Eric W. Weisstein_, May 17 2017

%H <a href="/A198634/b198634.txt">Table of n, a(n) for n = 1..12</a>

%H F. Hüffner, <a href="https://github.com/falk-hueffner/tinygraph">tinygraph</a>, software for generating integer sequences based on graph properties, version 4361e42

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/WeaklyPerfectGraph.html">Weakly Perfect Graph</a>

%F a(n) = A287009(n) + A287023(n).

%Y Cf. A287007, A287009, A287023.

%K nonn,more

%O 1,2

%A _Eric W. Weisstein_, Feb 19 2013

%E a(10) from _Eric W. Weisstein_, May 17 2017

%E a(11) added using tinygraph by _Falk Hüffner_, Aug 13 2017

%E a(12) added using tinygraph by _Jakub Jablonski_, Sep 26 2020