A227807 Number of rooted identity trees with n nodes and exactly 3 subtrees from the root.

1, 2, 5, 12, 28, 65, 152, 351, 818, 1907, 4460, 10453, 24581, 57922, 136860, 324088, 769188, 1829282, 4359048, 10406106, 24885240, 59607192, 142996100, 343540150, 826468374, 1990841497, 4801534221, 11593858684, 28025623617, 67816875039, 164268161404

Offset: 7

Author

Alois P. Heinz, Jul 31 2013

Keywords

• nonn

Examples

			:    o    :      o      o    :
:   /|\   :     /|\    /|\   :
:  o o o  :    o o o  o o o  :
:  | |    :   /| |    | |    :
:  o o    :  o o o    o o    :
:  |      :  |        |      :
:  o      :  o        o      :
:         :           |      :
:  n=7    :  n=8      o      :
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 7..800

Crossrefs

Column k=3 of A227774.