%I #30 Sep 08 2022 08:45:05
%S 1,7,16,13,25,10,4,28,31,19,1,7,16,13,25,10,4,28,31,19,1,7,16,13,25,
%T 10,4,28,31,19,1,7,16,13,25,10,4,28,31,19,1,7,16,13,25,10,4,28,31,19,
%U 1,7,16,13,25,10,4,28,31,19,1,7,16,13,25,10,4,28,31,19,1,7,16,13,25,10,4
%N a(n) = 7^n mod 33.
%H G. C. Greubel, <a href="/A070417/b070417.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (1,-1,1,-1,1,-1,1,-1,1).
%F From _R. J. Mathar_, Apr 20 2010: (Start)
%F a(n) = a(n-1) - a(n-2) + a(n-3) - a(n-4) + a(n-5) - a(n-6) + a(n-7) - a(n-8) + a(n-9).
%F G.f.: ( -1-6*x-10*x^2-3*x^3-22*x^4+12*x^5-16*x^6-12*x^7-19*x^8 ) / ( (x-1)*(1-x+x^2-x^3+x^4)*(1+x+x^2+x^3+x^4) ). (End)
%F a(n) = a(n-10). - _G. C. Greubel_, Mar 20 2016
%t PowerMod[7,Range[0,80],33] (* _Harvey P. Dale_, Mar 04 2015 *)
%o (Sage) [power_mod(7,n,33) for n in range(0,77)] # _Zerinvary Lajos_, Nov 27 2009
%o (PARI) a(n)=lift(Mod(7,33)^n) \\ _Charles R Greathouse IV_, Mar 22 2016
%o (Magma) [Modexp(7, n, 33): n in [0..100]]; // _Bruno Berselli_, Mar 22 2016
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, May 12 2002