Number of rooted trees where root has degree 4.

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =19a(5) =46a(6) =124a(7) =320a(8) =858a(9) =2282a(10) =6161a(11) =16647a(12) =45352a(13) =123861a(14) =340000a(15) =936098a(16) =2586518a(17) =7166394a(18) =19911638a(19) =55456892a(20) =154814055a(21) =433081632a(22) =1213901668a(23) =3408659401a(24) =9587879987a(25) =27011564035a(26) =76212078500