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

Author

N. J. A. Sloane, Jul 27 2011

Keywords

• nonn

Comments

See A003120 for definitions.

Links

• 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.