%I
%S 0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,8,0,0,0,0,0,0,1,7,28,0,0,0,0,0,1,
%T 6,21,56,0,0,0,0,1,5,15,35,70,0,0,0,1,4,10,20,35,56,0,0,1,3,6,
%U 10,15,21,28,0,1,2,3,4,5,6,7,8,1,1,1,1
%N 9section a(9n+k) gives kth differences of a for k=0..8 with a(n)=0 for n<8 and a(8)=1.
%H Alois P. Heinz, <a href="/A229659/b229659.txt">Table of n, a(n) for n = 0..10000</a>
%F a(9*n+k) = Sum_{j=0..k} (1)^j * C(k,j) * a(n+kj) for k=0..8.
%p a:= proc(n) option remember; local m, q;
%p m:= irem(n, 9, 'q'); `if`(n<9, `if`(n=8, 1, 0),
%p add(a(q+mj)*(1)^j*binomial(m, j), j=0..m))
%p end:
%p seq(a(n), n=0..100);
%Y Cf. A005590, A229653, A229654, A229655, A229656, A229657, A229658, A229660.
%K sign,look,eigen
%O 0,18
%A _Alois P. Heinz_, Sep 27 2013
