Number of 5-leaf rooted trees with n levels.

Terms

a(0) =1a(1) =7a(2) =27a(3) =75a(4) =170a(5) =336a(6) =602a(7) =1002a(8) =1575a(9) =2365a(10) =3421a(11) =4797a(12) =6552a(13) =8750a(14) =11460a(15) =14756a(16) =18717a(17) =23427a(18) =28975a(19) =35455a(20) =42966a(21) =51612a(22) =61502a(23) =72750a(24) =85475a(25) =99801a(26) =115857a(27) =133777a(28) =153700a(29) =175770