%I #11 Jan 19 2015 10:20:10
%S 1,2,4,11,32,136,749,6142,71759,1174550
%N Number of alternately colorable perfect graphs on n nodes.
%H S. Hougardy, <a href="http://www.or.uni-bonn.de/~hougardy/">Home Page</a>
%H S. Hougardy, <a href="http://dx.doi.org/10.1016/j.disc.2006.05.021">Classes of perfect graphs</a>, Discr. Math. 306 (2006), 2529-2571.
%K nonn,more
%O 1,2
%A _N. J. A. Sloane_, Oct 18 2006