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A292211 Number of (unlabeled) rooted trees with n leaf nodes and without unary nodes or outdegrees larger than five. 2
0, 1, 1, 2, 5, 12, 32, 87, 251, 733, 2201, 6696, 20705, 64681, 204183, 649738, 2082939, 6719063, 21796084, 71052001, 232645645, 764768959, 2523033061, 8350789334, 27721841968, 92277902858, 307935654094, 1029970333229, 3452371784462, 11595031966743 (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, 5)))

    end:

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

CROSSREFS

Column k=5 of A292085.

Sequence in context: A277863 A039809 A173611 * A293348 A188287 A148281

Adjacent sequences:  A292208 A292209 A292210 * A292212 A292213 A292214

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Sep 11 2017

STATUS

approved

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Last modified March 22 10:07 EDT 2019. Contains 321421 sequences. (Running on oeis4.)