Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #5 Aug 01 2014 12:36:18
%S 3,15,70,256,884,2840,8788,26238,76511,218462,614003,1702291,4667792,
%T 12678438,34163511,91424125,243210889,643652954,1695711086,4449529462,
%U 11634279616,30324707572,78819222196,204348623105,528597552113,1364545143938,3515960193715
%N Number of identity trees with n nodes where the maximal outdegree (branching factor) equals 6.
%H Alois P. Heinz, <a href="/A245751/b245751.txt">Table of n, a(n) for n = 20..1000</a>
%p b:= proc(n, i, t, k) option remember; `if`(n=0, 1,
%p `if`(i<1, 0, add(binomial(b(i-1$2, k$2), j)*
%p b(n-i*j, i-1, t-j, k), j=0..min(t, n/i))))
%p end:
%p a:= n-> b(n-1$2, 6$2) -b(n-1$2, 5$2):
%p seq(a(n), n=20..60);
%Y Column k=6 of A244523.
%K nonn
%O 20,1
%A _Joerg Arndt_ and _Alois P. Heinz_, Jul 31 2014