%I #11 Apr 27 2017 10:17:13
%S 1,2,2,1,1,0,1,1,1,2,0,2,0,1,2,2,1,1,0,1,1,1,2,0,2,0,1,2,2,1,1,0,1,1,
%T 1,2,0,2,0,1,2,2,1,1,0,1,1,1,2,0,2,0,1,2,2,1,1,0,1,1,1,2,0,2,0,1,2,2,
%U 1,1,0,1,1,1,2,0,2,0
%N Expansion of (1+x^2)/(1+x+x^4) mod 3.
%C Periodic with period (1, 2, 2, 1, 1, 0, 1, 1, 1, 2, 0, 2, 0).
%D Arthur Gill, Linear Sequential Circuits, McGraw-Hill, 1966, Eq. (17-11).
%H Colin Barker, <a href="/A285194/b285194.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_13">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,0,0,0,1).
%F From _Colin Barker_, Apr 27 2017: (Start)
%F G.f.: (2*x^11 + 2*x^9 + x^8 + x^7 + x^6 + x^4 + x^3 + 2*x^2 + 2*x + 1)/(1 - x^13).
%F a(n) = a(n-13) for n>12.
%F (End)
%p t5:=(1+x^2)/(1+x+x^4);
%p t6:=series(%,x,120):
%p t7:=seriestolist(%);
%p t8:=% mod 3;
%o (PARI) Vec((2*x^11 + 2*x^9 + x^8 + x^7 + x^6 + x^4 + x^3 + 2*x^2 + 2*x + 1)/(1 - x^13) + O(x^100)) \\ _Colin Barker_, Apr 27 2017
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Apr 26 2017