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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 (list; graph; refs; listen; history; text; internal format)
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
Sequence in context: A076316 A304125 A082104 * A287007 A369843 A099215
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

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Last modified April 25 10:22 EDT 2024. Contains 371967 sequences. (Running on oeis4.)