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A292215 Number of (unlabeled) rooted trees with n leaf nodes and without unary nodes or outdegrees larger than nine. 2
0, 1, 1, 2, 5, 12, 33, 90, 261, 766, 2311, 7065, 21955, 68921, 218640, 699161, 2252410, 7301482, 23802026, 77973162, 256565366, 847555502, 2809934472, 9346232579, 31179372180, 104298865434, 349766936468, 1175657140783, 3960143985167, 13366048810561 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Index entries for sequences related to rooted trees

MAPLE

b:= proc(n, i, v) option remember; `if`(n=0,

      `if`(v=0, 1, 0), `if`(i<1 or v<1 or n<v, 0,

      `if`(v=n, 1, add(binomial(a(i)+j-1, j)*

       b(n-i*j, i-1, v-j), j=0..min(n/i, v)))))

    end:

a:= proc(n) option remember; `if`(n<2, n,

      add(b(n, n+1-j, j), j=2..min(n, 9)))

    end:

seq(a(n), n=0..35);

CROSSREFS

Column k=9 of A292085.

Sequence in context: A292213 A032124 A292214 * A292216 A000669 A295461

Adjacent sequences:  A292212 A292213 A292214 * A292216 A292217 A292218

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Sep 11 2017

STATUS

approved

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Last modified March 25 12:11 EDT 2019. Contains 321470 sequences. (Running on oeis4.)