cp's OEIS Frontend

A245751 Number of identity trees with n nodes where the maximal outdegree (branching factor) equals 6.

%I A245751 #5 Aug 01 2014 12:36:18
%S A245751 3,15,70,256,884,2840,8788,26238,76511,218462,614003,1702291,4667792,
%T A245751 12678438,34163511,91424125,243210889,643652954,1695711086,4449529462,
%U A245751 11634279616,30324707572,78819222196,204348623105,528597552113,1364545143938,3515960193715
%N A245751 Number of identity trees with n nodes where the maximal outdegree (branching factor) equals 6.
%H A245751 Alois P. Heinz, <a href="/A245751/b245751.txt">Table of n, a(n) for n = 20..1000</a>
%p A245751 b:= proc(n, i, t, k) option remember; `if`(n=0, 1,
%p A245751       `if`(i<1, 0, add(binomial(b(i-1$2, k$2), j)*
%p A245751        b(n-i*j, i-1, t-j, k), j=0..min(t, n/i))))
%p A245751     end:
%p A245751 a:= n-> b(n-1$2, 6$2) -b(n-1$2, 5$2):
%p A245751 seq(a(n), n=20..60);
%Y A245751 Column k=6 of A244523.
%K A245751 nonn
%O A245751 20,1
%A A245751 _Joerg Arndt_ and _Alois P. Heinz_, Jul 31 2014