A258479 - OEIS

%I #4 May 31 2015 11:50:29

%S 1,11,67,298,1080,3379,9453,24204,57658,129335,275693,562454,1104484,

%T 2097247,3865383,6937016,12154390,20838939,35029203,57829458,93897437,

%U 150150058,236723504,368350864,566187387,860416074,1293614426,1925547270,2839214222,4149449828

%N Number of partitions of n into two sorts of parts having exactly 9 parts of the second sort.

%H Alois P. Heinz, <a href="/A258479/b258479.txt">Table of n, a(n) for n = 9..1000</a>

%p b:= proc(n, i) option remember; series(`if`(n=0, 1,

%p       `if`(i<1, 0, add(b(n-i*j, i-1)*add(x^t*

%p        binomial(j, t), t=0..min(9, j)), j=0..n/i))), x, 10)

%p     end:

%p a:= n-> coeff(b(n$2), x, 9):

%p seq(a(n), n=9..40);

%Y Column k=9 of A256193.

%K nonn

%O 9,2

%A _Alois P. Heinz_, May 31 2015