%I #18 Sep 03 2021 05:55:37

%S 1,1,2,6,20,103,706,7423,116476,2730992,92711668,4435835227

%N Number of unlabeled and connected graphs which are weakly chordal. (G is weakly chordal iff there are no induced cycles of size 5 or more in G nor in its complement.)

%C Also known as the "weakly triangulated" graphs. Contains the chordal and cochordal graphs and is contained in the class of Perfect graphs.

%H R. Hayward, <a href="http://dx.doi.org/10.1016/0095-8956(85)90050-4">Weakly triangulated graphs</a>, Journal Comb. Theory (Series B) 39 (1985) 200-208.

%H R. Hayward, <a href="https://webdocs.cs.ualberta.ca/~hayward/papers/trcs0193.ps">Generating Weakly Triangulated Graphs</a>, Journal of Graph Theory 21 (1996) 67-69.

%H R. Hayward, J. Spinrad, R. Sritharan, <a href="https://webdocs.cs.ualberta.ca/~hayward/papers/sodaHndl.ps">Weakly Chordal Graph Algorithms via Handles</a>, Proc. 11th SODA (2000) 42-49.

%H F. Hüffner, <a href="https://github.com/falk-hueffner/tinygraph">tinygraph</a>, software for generating integer sequences based on graph properties, version 26b03c7

%F Inverse Euler transform of A123472.

%K more,nonn

%O 1,3

%A _Jim Nastos_, Jan 13 2003

%E a(10)-a(12) added using tinygraph by _Falk Hüffner_, Jan 15 2016