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A244705 Number of n-node unlabeled rooted trees with thinning limbs and root outdegree (branching factor) 4. 2
1, 1, 3, 6, 15, 29, 68, 140, 312, 660, 1443, 3084, 6710, 14425, 31278, 67508, 146300, 316424, 685955, 1486008, 3223480, 6992012, 15179437, 32960891, 71617874, 155661971, 338508703, 736401503, 1602712182, 3489454243, 7600403101, 16560519877, 36097320801 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,3

COMMENTS

In a rooted tree with thinning limbs the outdegree of a parent node is larger than or equal to the outdegree of any of its child nodes.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 5..1000

MAPLE

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

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

      `if`(n=v, 1, add(binomial(A(i, min(i-1, h))+j-1, j)

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

    end:

A:= proc(n, k) option remember;

      `if`(n<2, n, add(b(n-1$2, j$2), j=1..min(k, n-1)))

    end:

a:= n-> b(n-1$2, 4$2):

seq(a(n), n=5..50);

CROSSREFS

Column k=4 of A244657.

Sequence in context: A034464 A116696 A000220 * A319643 A092641 A077449

Adjacent sequences:  A244702 A244703 A244704 * A244706 A244707 A244708

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Jul 04 2014

STATUS

approved

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Last modified December 14 14:20 EST 2019. Contains 329979 sequences. (Running on oeis4.)