Number of unlabeled rooted trees with n vertices and more than two branches of the root.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =2a(5) =5a(6) =12a(7) =30a(8) =75a(9) =194a(10) =501a(11) =1317a(12) =3485a(13) =9302a(14) =24976a(15) =67500a(16) =183290a(17) =500094a(18) =1369939a(19) =3766831a(20) =10391722a(21) =28756022a(22) =79794407a(23) =221987348a(24) =619019808a(25) =1729924110a(26) =4844242273a(27) =13590663071a(28) =38195831829a(29) =107523305566