Number of shapes of balanced 9-ary trees with n nodes, where a tree is balanced if the total number of nodes in subtrees corresponding to the branches of any node differ by at most one.
A229394
Number of shapes of balanced 9-ary trees with n nodes, where a tree is balanced if the total number of nodes in subtrees corresponding to the branches of any node differ by at most one.
Terms
- a(0) =1a(1) =1a(2) =9a(3) =36a(4) =84a(5) =126a(6) =126a(7) =84a(8) =36a(9) =9a(10) =1a(11) =81a(12) =2916a(13) =61236a(14) =826686a(15) =7440174a(16) =44641044a(17) =172186884a(18) =387420489a(19) =387420489a(20) =13947137604a(21) =223154201664
External references
- oeis: A229394