Number of sequences of rooted identity trees with a total of n nodes.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =20a(6) =46a(7) =107a(8) =252a(9) =597a(10) =1425a(11) =3418a(12) =8235a(13) =19910a(14) =48287a(15) =117412a(16) =286150a(17) =698771a(18) =1709403a(19) =4188258a(20) =10276221a(21) =25245406a(22) =62091122a(23) =152872521a(24) =376741574a(25) =929260598a(26) =2293936762a(27) =5666939995a(28) =14009267368a(29) =34654583662