a(n) is the number of forests with n (unlabeled) nodes in which each component tree is planted, that is, is a rooted tree in which the root has degree 1.
A005198
a(n) is the number of forests with n (unlabeled) nodes in which each component tree is planted, that is, is a rooted tree in which the root has degree 1.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =3a(4) =5a(5) =13a(6) =27a(7) =68a(8) =160a(9) =404a(10) =1010a(11) =2604a(12) =6726a(13) =17661a(14) =46628a(15) =124287a(16) =333162a(17) =898921a(18) =2437254a(19) =6640537a(20) =18166568a(21) =49890419a(22) =137478389a(23) =380031868a(24) =1053517588a(25) =2928246650a(26) =8158727139a(27) =22782938271a(28) =63752461474a(29) =178740014515
External references
- oeis: A005198