login
A245142
Number of n-node unlabeled rooted trees with thickening limbs and root outdegree (branching factor) 2.
2
1, 0, 1, 1, 3, 3, 8, 9, 21, 28, 56, 81, 159, 237, 444, 701, 1273, 2060, 3699, 6099, 10840, 18180, 32079, 54417, 95787, 163868, 287914, 496171, 871270, 1509676, 2652068, 4615810, 8114578, 14176261, 24947471, 43718822, 77031659, 135350915, 238791685, 420544851
OFFSET
3,5
LINKS
CROSSREFS
Column k=2 of A245151.
Sequence in context: A092481 A099508 A141577 * A123315 A237113 A293937
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jul 12 2014
STATUS
approved