%I #7 Jul 30 2015 22:17:28
%S 1,0,1,0,1,0,1,0,1,1,2,1,2,1,2,1,2,1,3,2,4,2,4,2,4,2,4,3,5,4,6,4,6,4,
%T 6,4,7,5,8,6,9,6,9,6,9,7,10,8,11,9,12,9,12,9,13,10,14,11,15,12,16,12,
%U 16,13,17,14,18,15,19,16,20,16
%N Expansion of 1/((1-x^2)(1-x^9)(1-x^10)).
%H <a href="/index/Rec#order_21">Index entries for linear recurrences with constant coefficients</a>, signature (0, 1, 0, 0, 0, 0, 0, 0, 1, 1, -1, -1, 0, 0, 0, 0, 0, 0, -1, 0, 1).
%F a(0)=1, a(1)=0, a(2)=1, a(3)=0, a(4)=1, a(5)=0, a(6)=1, a(7)=0, a(8)=1, a(9)=1, a(10)=2, a(11)=1, a(12)=2, a(13)=1, a(14)=2, a(15)=1, a(16)=2, a(17)=1, a(18)=3, a(19)=2, a(20)=4, a(n)=a(n-2)+a(n-9)+a(n-10)- a(n-11)- a(n-12)-a(n-19)+a(n-21). - _Harvey P. Dale_, Oct 15 2013
%t CoefficientList[Series[1/((1-x^2)(1-x^9)(1-x^10)),{x,0,80}],x] (* or *) LinearRecurrence[{0,1,0,0,0,0,0,0,1,1,-1,-1,0,0,0,0,0,0,-1,0,1},{1,0,1,0,1,0,1,0,1,1,2,1,2,1,2,1,2,1,3,2,4},80] (* _Harvey P. Dale_, Oct 15 2013 *)
%K nonn
%O 0,11
%A _N. J. A. Sloane_.