Number of P_4-sparse perfect graphs on n nodes.

Terms

a(0) =1a(1) =2a(2) =4a(3) =11a(4) =27a(5) =78a(6) =218a(7) =653a(8) =1963a(9) =6088a(10) =19078a(11) =60825a(12) =195757a(13) =636810a(14) =2087764a(15) =6896119