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A198634
Number of weakly perfect graphs on n nodes.
4
1, 2, 4, 11, 33, 152, 1006, 11805, 257542, 11011758, 917095022, 145164791300
OFFSET
1,2
COMMENTS
A graph is weakly perfect if it has equal chromatic and clique numbers.
First differs from A287007 (fractional chromatic number equals chromatic number) at a(8). - Eric W. Weisstein, May 17 2017
LINKS
F. Hüffner, tinygraph, software for generating integer sequences based on graph properties, version 4361e42
Eric Weisstein's World of Mathematics, Weakly Perfect Graph
FORMULA
a(n) = A287009(n) + A287023(n).
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Eric W. Weisstein, Feb 19 2013
EXTENSIONS
a(10) from Eric W. Weisstein, May 17 2017
a(11) added using tinygraph by Falk Hüffner, Aug 13 2017
a(12) added using tinygraph by Jakub Jablonski, Sep 26 2020
STATUS
approved