a(n) is the number of unlabeled forests of rooted trees with n nodes such that no two trees are identical.

A052827

a(n) is the number of unlabeled forests of rooted trees with n nodes such that no two trees are identical.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =3a(4) =6a(5) =15a(6) =36a(7) =90a(8) =225a(9) =578a(10) =1492a(11) =3901a(12) =10278a(13) =27313a(14) =73042a(15) =196585a(16) =531847a(17) =1445991a(18) =3948282a(19) =10823524a(20) =29776129a(21) =82183115a(22) =227501127a(23) =631494797a(24) =1757297207a(25) =4901491697a(26) =13700742034a(27) =38373104938a(28) =107675540083a(29) =302664162746

External references