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A245124 Number of n-node rooted identity trees with thinning limbs and root outdegree (branching factor) 5. 2
1, 4, 11, 28, 70, 160, 366, 804, 1748, 3734, 7918, 16597, 34601, 71628, 147631, 302857, 619231, 1261849, 2564795, 5200248, 10522565, 21252174, 42854194, 86286963, 173517189, 348523105, 699311092, 1401837776, 2807733181, 5619221464, 11238041122, 22460777472 (list; graph; refs; listen; history; text; internal format)
OFFSET

15,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 15..750

EXAMPLE

a(15) = 1:

:        o        :

:   / (  |  ) \   :

:  o  o  o  o  o  :

:  | ( ) |  |     :

:  o o o o  o     :

:  | |   |        :

:  o o   o        :

:  |              :

:  o              :

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, add(binomial(A(i, min(i-1, h)), 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, 5$2):

seq(a(n), n=15..50);

CROSSREFS

Column k=5 of A245120.

Sequence in context: A099326 A127985 A005409 * A020964 A113067 A290890

Adjacent sequences:  A245121 A245122 A245123 * A245125 A245126 A245127

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Jul 12 2014

STATUS

approved

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Last modified July 23 13:58 EDT 2019. Contains 325254 sequences. (Running on oeis4.)