%I #7 Jan 15 2016 16:24:17
%S 1,1,2,6,19,87,454,3006,23509,220102,2450511,32773345,532120179
%N Number of unlabeled and connected graphs on n vertices which are HH-free ("house-hole-free").
%C Also characterized as Weakly Chordal Meyniel graphs or P5-free Weakly Chordal graphs.
%D R. Hayward, Meyniel Weakly Triangulated Graphs I: Co-perfect orderability Discrete Applied Mathematics 73 (1997) 199-210
%H F. Hüffner, <a href="https://github.com/falk-hueffner/tinygraph">tinygraph</a>, software for generating integer sequences based on graph properties, version 5926e72.
%K more,nonn
%O 1,3
%A _Jim Nastos_, Jan 13 2003
%E Corrected by _Jim Nastos_, Jan 20 2003
%E a(10)-a(13) added using tinygraph by _Falk Hüffner_, Jan 15 2016