cp's OEIS Frontend

A318797 Number of rooted trees with n nodes such that no more than three subtrees of the same size extend from the same node.

%I A318797 #6 Sep 03 2018 20:55:01
%S A318797 0,1,1,2,4,8,18,43,102,250,623,1579,4042,10470,27350,72034,190956,
%T A318797 509259,1365271,3677522,9947145,27007988,73582758,201103314,551190098,
%U A318797 1514683667,4172470962,11519509386,31869341642,88337853393,245301368188,682307613945
%N A318797 Number of rooted trees with n nodes such that no more than three subtrees of the same size extend from the same node.
%H A318797 Alois P. Heinz, <a href="/A318797/b318797.txt">Table of n, a(n) for n = 0..2158</a>
%p A318797 g:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0, add(
%p A318797       binomial(g((i-1)$2)+j-1, j)*g(n-i*j, i-1), j=0..min(3, n/i))))
%p A318797     end:
%p A318797 a:= n-> g((n-1)$2):
%p A318797 seq(a(n), n=0..40);
%Y A318797 Column k=3 of A318753.
%K A318797 nonn
%O A318797 0,4
%A A318797 _Alois P. Heinz_, Sep 03 2018