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

Author

Alois P. Heinz, Jul 12 2014

Keywords

• nonn

Examples

			a(15) = 1:
:        o        :
:   / (  |  ) \   :
:  o  o  o  o  o  :
:  | ( ) |  |     :
:  o o o o  o     :
:  | |   |        :
:  o o   o        :
:  |              :
:  o              :
		

Links

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

Crossrefs

Column k=5 of A245120.

Programs

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 b(n-1$2, 5$2):
seq(a(n), n=15..50);