A193487 Number of rooted trees with n nodes and omega-valency 2.

0, 0, 0, 1, 1, 5, 9, 29, 62, 181, 422, 1166, 2885, 7788, 19893, 53319, 138931, 372027, 982379, 2635898, 7026483, 18914903, 50781803, 137201419, 370442111, 1004512375, 2724867782, 7414635185, 20193165834, 55125632502

Offset

1,6

Comments

See A003120 for definitions.

Links

Table of n, a(n) for n=1..30.

J.-C. Arditti, Dénombrement des arborescences dont le graphe de comparabilité est Hamiltonien, Discrete Math., 5 (1973), 189-200.

Crossrefs

Cf. A003120, A193488, A193489, A193490, A193491.

Sequence in context: A163779 A280487 A191013 * A006131 A352008 A270595

Adjacent sequences: A193484 A193485 A193486 * A193488 A193489 A193490

Keyword

nonn

Author

N. J. A. Sloane, Jul 27 2011

Status

approved