Number of simple unlabeled graphs on n nodes with exactly 4 connected components that are trees or cycles.

A215984

Number of simple unlabeled graphs on n nodes with exactly 4 connected components that are trees or cycles.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =6a(4) =13a(5) =25a(6) =53a(7) =106a(8) =224a(9) =475a(10) =1037a(11) =2315a(12) =5302a(13) =12382a(14) =29495a(15) =71450a(16) =175618a(17) =437272a(18) =1101000a(19) =2799768a(20) =7181703a(21) =18565546a(22) =48326482a(23) =126581749a(24) =333424119a(25) =882765486a(26) =2348114866a(27) =6272676477a(28) =16822741588a(29) =45281587081

External references