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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. 2
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 (list; graph; refs; listen; history; text; internal format)
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);

CROSSREFS

Column k=10 of A221857.

Sequence in context: A001488 A009540 A010926 * A306965 A045852 A226450

Adjacent sequences:  A229392 A229393 A229394 * A229396 A229397 A229398

KEYWORD

nonn,look

AUTHOR

Alois P. Heinz, Sep 21 2013

STATUS

approved

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Last modified April 23 14:15 EDT 2019. Contains 322386 sequences. (Running on oeis4.)