Total number of fixed points in free homeomorphically irreducible trees with n nodes.

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =3a(7) =5a(8) =10a(9) =16a(10) =38a(11) =66a(12) =143a(13) =268a(14) =564a(15) =1100a(16) =2282a(17) =4546a(18) =9382a(19) =18977a(20) =39112a(21) =79891a(22) =164917a(23) =339195a(24) =702041a(25) =1451628a(26) =3013442a(27) =6257561a(28) =13029327a(29) =27152492