Number of simple unlabeled graphs on n nodes with exactly 2 connected components that are trees or cycles.

A215982

Number of simple unlabeled graphs on n nodes with exactly 2 connected components that are trees or cycles.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =5a(4) =10a(5) =17a(6) =33a(7) =62a(8) =127a(9) =267a(10) =587a(11) =1326a(12) =3085a(13) =7326a(14) =17731a(15) =43585a(16) =108563a(17) =273544a(18) =696113a(19) =1787042a(20) =4623125a(21) =12043071a(22) =31565842a(23) =83200763a(24) =220413272a(25) =586625403a(26) =1567930743a(27) =4207181144a(28) =11329835687a(29) =30613313339

External references