Number of unlabeled balanced rooted semi-identity trees with n nodes.

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =4a(6) =6a(7) =8a(8) =12a(9) =16a(10) =25a(11) =35a(12) =53a(13) =77a(14) =117a(15) =173a(16) =265a(17) =396a(18) =605a(19) =919a(20) =1408a(21) =2147a(22) =3305a(23) =5070a(24) =7819a(25) =12049a(26) =18635a(27) =28811a(28) =44672a(29) =69264