Number of binary trees of path length n.

Terms

a(0) =1a(1) =2a(2) =1a(3) =4a(4) =4a(5) =2a(6) =14a(7) =8a(8) =12a(9) =28a(10) =21a(11) =52a(12) =52a(13) =72a(14) =92a(15) =160a(16) =212a(17) =178a(18) =446a(19) =360a(20) =628a(21) =920a(22) =918a(23) =1568a(24) =1784a(25) =2676a(26) =2960a(27) =4724a(28) =5360a(29) =7280