A227808 Number of rooted identity trees with n nodes and exactly 4 subtrees from the root.

2, 4, 13, 34, 91, 225, 571, 1403, 3466, 8468, 20703, 50389, 122673, 298090, 724433, 1759595, 4274819, 10385533, 25240007, 61358410, 149226407, 363077813, 883818374, 2152462147, 5244790003, 12786162151, 31187100089, 76108058977, 185825963102, 453940832229

Offset: 11

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       :
:                 |          :
:  n=11           o          :
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 11..800

Crossrefs

Column k=4 of A227774.