A245124 Number of n-node rooted identity trees with thinning limbs and root outdegree (branching factor) 5.

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

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: A127985 A339252 A005409 * A020964 A113067 A290890

Adjacent sequences: A245121 A245122 A245123 * A245125 A245126 A245127

Keyword

nonn

Author

Alois P. Heinz, Jul 12 2014

Status

approved