Number of 6-leaf rooted trees with n levels.

Terms

a(0) =0a(1) =1a(2) =11a(3) =58a(4) =206a(5) =571a(6) =1337a(7) =2772a(8) =5244a(9) =9237a(10) =15367a(11) =24398a(12) =37258a(13) =55055a(14) =79093a(15) =110888a(16) =152184a(17) =204969a(18) =271491a(19) =354274a(20) =456134a(21) =580195a(22) =729905a(23) =909052a(24) =1121780a(25) =1372605a(26) =1666431a(27) =2008566a(28) =2404738a(29) =2861111