Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #17 Sep 03 2021 05:55:48
%S 1,1,2,6,18,63,213,763,2716,9874,36162,134328,503500,1905675,7267269,
%T 27906062
%N Number of unlabeled and connected graphs on n vertices which are semi-P4-sparse (G is semi-P4-sparse iff G has no induced P5, House, or complement of a fork).
%H Jean-Luc Fouquet and Vassilis Giakoumakis, <a href="http://dx.doi.org/10.1016/S0012-365X(96)00177-X">On semi-P4-sparse graphs</a>, Discrete Mathematics 165/166 (1997) 277-300.
%H F. Hüffner, <a href="https://github.com/falk-hueffner/tinygraph">tinygraph</a>, software for generating integer sequences based on graph properties, version 69d4186.
%K more,nonn
%O 1,3
%A _Jim Nastos_, Jan 14 2003
%E Corrected by _Jim Nastos_, Jan 20 2003
%E a(10)-a(16) added using tinygraph by _Falk Hüffner_, Jan 16 2016