%I #10 Jan 20 2016 04:19:21
%S 0,0,0,1,1,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,
%T 0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,
%U 0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0
%N Number of unlabeled, connected graphs on n vertices that are prime and have no induced subgraph isomorphic to a bull, a P5 or a P5bar.
%C a(4) = 1 is the P_4, a(5) = 1 is the C_5, and a(n) = 2 for even n >= 6 are the unique prime bipartite chain graph on n vertices and its complement.  _Falk Hüffner_, Jan 18 2016
%H J. L. Fouquet, <a href="http://dx.doi.org/10.1016/0012365X(93)905396">A Decomposition for a class of (P5,P5bar)free graphs</a>, Discrete Math. 121 (1993) 7583.
%Y Cf. A079577 (without "prime" requirement)
%K nonn,easy
%O 1,6
%A _Falk Hüffner_, Jan 18 2016
