Number of graphs with n nodes, n-2 edges and no isolated vertices.

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =15a(5) =33a(6) =83a(7) =202a(8) =527a(9) =1377a(10) =3744a(11) =10335a(12) =29297a(13) =84396a(14) =248034a(15) =740289a(16) =2245094a(17) =6904206a(18) =21522973a(19) =67936799a(20) =217026480a(21) =701159919a(22) =2289925258a(23) =7556363054a(24) =25184139149a(25) =84743377436a(26) =287815771822a(27) =986345040471