Number of unlabeled rooted trees with n nodes in which all positive outdegrees are different.

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =5a(6) =13a(7) =15a(8) =23a(9) =34a(10) =95a(11) =106a(12) =176a(13) =241a(14) =374a(15) =942a(16) =1129a(17) =1760a(18) =2515a(19) =3711a(20) =5136a(21) =12857a(22) =14911a(23) =23814a(24) =33002a(25) =49141a(26) =65798a(27) =97056a(28) =209707a(29) =255042