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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 (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

Eric W. Weisstein, Table of n, a(n) for n = 1..9

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: A052431 A076316 A082104 * A287007 A099215 A089407

Adjacent sequences:  A198631 A198632 A198633 * A198635 A198636 A198637

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

STATUS

approved

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Last modified November 18 00:38 EST 2017. Contains 294837 sequences.