Number of rooted unlabeled ordered (plane) trees with 2n leaves such that i) every internal node has an even number of children and ii) every path from the root to a leaf is the same length.
A219226
Number of rooted unlabeled ordered (plane) trees with 2n leaves such that i) every internal node has an even number of children and ii) every path from the root to a leaf is the same length.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =3a(4) =6a(5) =13a(6) =29a(7) =65a(8) =147a(9) =337a(10) =785a(11) =1857a(12) =4452a(13) =10789a(14) =26365a(15) =64833a(16) =160167a(17) =397025a(18) =986593a(19) =2456193a(20) =6123726a(21) =15286021a(22) =38198573a(23) =95555937a(24) =239294222a(25) =599914489a(26) =1505750425a(27) =3783967201a(28) =9521244242a(29) =23988787485
External references
- oeis: A219226