Number of rooted trees with n nodes, most of which are leaves.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =4a(5) =5a(6) =20a(7) =28a(8) =110a(9) =169a(10) =663a(11) =1078a(12) =4217a(13) =7169a(14) =27979a(15) =49191a(16) =191440a(17) =345771a(18) =1341974a(19) =2477719a(20) =9589567a(21) =18034670a(22) =69612556a(23) =132984290a(24) =511987473a(25) =991391707a(26) =3807503552a(27) =7460270591a(28) =28585315026a(29) =56595367747