Number of trimmed trees with n nodes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =0a(4) =1a(5) =1a(6) =2a(7) =3a(8) =6a(9) =10a(10) =21a(11) =39a(12) =82a(13) =167a(14) =360a(15) =766a(16) =1692a(17) =3726a(18) =8370a(19) =18866a(20) =43029a(21) =98581a(22) =227678a(23) =528196a(24) =1232541a(25) =2888142a(26) =6798293a(27) =16061348a(28) =38086682a(29) =90607902