Shapes of height-balanced AVL trees of height at most 5 with n nodes.

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =1a(5) =4a(6) =6a(7) =4a(8) =17a(9) =32a(10) =44a(11) =60a(12) =70a(13) =184a(14) =476a(15) =872a(16) =1553a(17) =2720a(18) =4288a(19) =6312a(20) =9004a(21) =11992a(22) =14372a(23) =15400a(24) =14630a(25) =11968a(26) =8104a(27) =4376a(28) =1820a(29) =560