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 A303271 Number of ordered rooted trees with n non-root nodes such that the maximal outdegree equals three. 2

%I

%S 1,4,15,53,182,616,2070,6930,23166,77429,258973,867230,2908633,

%T 9772556,32896088,110949072,374934201,1269505482,4306750577,

%U 14638006449,49843505965,170021694271,580954640775,1988357053020,6816047416230,23400699072231,80455436055699

%N Number of ordered rooted trees with n non-root nodes such that the maximal outdegree equals three.

%H Alois P. Heinz, <a href="/A303271/b303271.txt">Table of n, a(n) for n = 3..1802</a>

%F a(n) = A036765(n) - A001006(n).

%p b:= proc(u, o, k) option remember; `if`(u+o=0, 1,

%p add(b(u-j, o+j-1, k), j=1..min(1, u))+

%p add(b(u+j-1, o-j, k), j=1..min(k, o)))

%p end:

%p a:= n-> b(0, n, 3)-b(0, n, 2):

%p seq(a(n), n=3..35);

%Y Column k=3 of A203717.

%Y Cf. A001006, A036765.

%K nonn

%O 3,2

%A _Alois P. Heinz_, Apr 20 2018

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Last modified December 14 07:03 EST 2019. Contains 329978 sequences. (Running on oeis4.)