Number of 8-leaf rooted trees with n levels.

Terms

a(0) =0a(1) =1a(2) =22a(3) =223a(4) =1344a(5) =5727a(6) =19193a(7) =54046a(8) =133476a(9) =297633a(10) =611644a(11) =1175845a(12) =2138500a(13) =3711279a(14) =6187767a(15) =9965276a(16) =15570232a(17) =23687409a(18) =35193282a(19) =51193771a(20) =73066648a(21) =102508879a(22) =141589173a(23) =192806010a(24) =259151420a(25) =344180785a(26) =452088936a(27) =587792817a(28) =757020988a(29) =966410239