Number of rooted trees with n nodes and omega-valency 4.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =1a(7) =7a(8) =13a(9) =55a(10) =127a(11) =435a(12) =1110a(13) =3458a(14) =9261a(15) =27460a(16) =75305a(17) =217619a(18) =603618a(19) =1720712a(20) =4799095a(21) =13580179a(22) =37979149a(23) =107045222a(24) =299800569a(25) =843242264a(26) =2363693561a(27) =6641675073a(28) =18628827667a(29) =52325428340