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Number of rooted trees with n nodes and omega-valency 2.
5

%I #10 Feb 18 2018 02:49:30

%S 0,0,0,1,1,5,9,29,62,181,422,1166,2885,7788,19893,53319,138931,372027,

%T 982379,2635898,7026483,18914903,50781803,137201419,370442111,

%U 1004512375,2724867782,7414635185,20193165834,55125632502

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

%C See A003120 for definitions.

%H J.-C. Arditti, <a href="http://dx.doi.org/10.1016/0012-365X(73)90135-0">Dénombrement des arborescences dont le graphe de comparabilité est Hamiltonien</a>, Discrete Math., 5 (1973), 189-200.

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

%K nonn

%O 1,6

%A _N. J. A. Sloane_, Jul 27 2011