Number of rooted trees with n nodes and 4 leaves.

Terms

a(0) =1a(1) =4a(2) =14a(3) =39a(4) =97a(5) =212a(6) =429a(7) =804a(8) =1427a(9) =2406a(10) =3900a(11) =6094a(12) =9245a(13) =13645a(14) =19682a(15) =27791a(16) =38530a(17) =52516a(18) =70521a(19) =93390a(20) =122157a(21) =157945a(22) =202104a(23) =256090a(24) =321628a(25) =400567a(26) =495070a(27) =607445a(28) =740362a(29) =896657