A229395 - OEIS

A229395

Number of shapes of balanced 10-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.

1, 1, 10, 45, 120, 210, 252, 210, 120, 45, 10, 1, 100, 4500, 120000, 2100000, 25200000, 210000000, 1200000000, 4500000000, 10000000000, 10000000000, 450000000000, 9112500000000, 109350000000000, 861131250000000, 4650108750000000, 17437907812500000

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OFFSET

0,3

COMMENTS

a(n) = 1 for n in { A002275 }.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1111

MAPLE

a:= proc(n) option remember; local m, r; if n<2 then 1 else

r:= iquo(n-1, 10, 'm'); binomial(10, m) *a(r+1)^m *a(r)^(10-m) fi

end:

seq(a(n), n=0..111);