Numbers of uniquely embeddable trees on n vertices.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =10a(7) =19a(8) =31a(9) =57a(10) =95a(11) =161a(12) =262a(13) =435a(14) =683a(15) =1081a(16) =1665a(17) =2545a(18) =3800a(19) =5658a(20) =8232a(21) =11935a(22) =17012a(23) =24074a(24) =33606a(25) =46698a(26) =63994a(27) =87281a(28) =117797a(29) =158121