%I #22 Dec 18 2023 14:23:38
%S 1,2,4,8,16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38,31,17,34,23,1,2,
%T 4,8,16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38,31,17,34,23,1,2,4,8,
%U 16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38
%N a(n) = 2^n mod 45.
%H G. C. Greubel, <a href="/A070350/b070350.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
%F From _R. J. Mathar_, Feb 06 2011: (Start)
%F a(n) = a(n-12).
%F G.f.: (-1-2*x-4*x^2-8*x^3-16*x^4-32*x^5-19*x^6-38*x^7-31*x^8 -17*x^9 -34*x^10-23*x^11 ) / ( (x-1)*(1+x+x^2)*(1+x)*(1-x+x^2)*(1+x^2)*(x^4-x^2+1) ). (End)
%t PowerMod[2, Range[0, 50], 45] (* _G. C. Greubel_, Mar 11 2016 *)
%o (PARI) a(n)=lift(Mod(2,45)^n) \\ _Charles R Greathouse IV_, Mar 22 2016
%o (GAP) List([0..79],n->PowerMod(2,n,45)); # _Muniru A Asiru_, Jan 30 2019
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, May 12 2002