OFFSET
1,2
COMMENTS
A graph is called Hoang if its wing graph is bipartite. The wing graph W(G) of a graph G has as its vertices the edges of G and two edges are adjacent in W(G) if there is an induced P4 in G that has these two edges as its ends. - Falk Hüffner, Jun 30 2018
LINKS
S. Hougardy, Classes of perfect graphs, Discr. Math. 306 (2006), 2529-2571.
F. Hüffner, tinygraph, software for generating integer sequences based on graph properties, version 6c1dbe4.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 18 2006
EXTENSIONS
a(11)-a(12) added using tinygraph by Falk Hüffner, Jun 30 2018
STATUS
approved