Number of graphs with n nodes and n+2 edges.

Terms

a(0) =1a(1) =4a(2) =24a(3) =131a(4) =663a(5) =3252a(6) =15772a(7) =75415a(8) =359307a(9) =1711908a(10) =8191607a(11) =39500169a(12) =192525021a(13) =950868860a(14) =4769060224a(15) =24331970791a(16) =126457607026a(17) =670143402073