A244463 - OEIS

%I #5 Jul 01 2014 19:35:37

%S 1,0,0,0,0,0,0,0,0,1,2,2,2,2,2,2,2,2,4,7,12,16,21,25,30,34,39,47,61,

%T 83,117,160,215,280,356,442,549,682,864,1112,1458,1919,2533,3313,4298,

%U 5521,7057,8995,11497,14751,19042,24687,32102,41731,54172,70112,90535

%N Number of unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 9.

%H Alois P. Heinz, <a href="/A244463/b244463.txt">Table of n, a(n) for n = 10..900</a>

%p b:= proc(n, i, t, k) option remember; `if`(n=0, `if`(t in [0, k],

%p       1, 0), `if`(i<1 or t>n, 0, add(binomial(b((i-1)$2, k$2)+j-1, j)*

%p       b(n-i*j, i-1, max(0,t-j), k), j=0..n/i)))

%p     end:

%p a:= n-> b(n-1$2, 9$2) -b(n-1$2, 10$2):

%p seq(a(n), n=10..75);

%Y Column k=9 of A244454.

%Y Cf. A244538.

%K nonn

%O 10,11

%A _Joerg Arndt_ and _Alois P. Heinz_, Jun 29 2014