%I #35 Dec 25 2023 11:24:21
%S 1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,
%T 5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,
%U 3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15,9,1,5,3,15
%N a(n) = 5^n mod 22.
%H G. C. Greubel, <a href="/A070375/b070375.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,1).
%F From _R. J. Mathar_, Apr 20 2010: (Start)
%F a(n) = a(n-5).
%F G.f.: ( -1-5*x-3*x^2-15*x^3-9*x^4 ) / ( (x-1)*(1+x+x^2+x^3+x^4) ). (End)
%p A070375:=n->5^n mod 22: seq(A070375(n), n=0..100); # _Wesley Ivan Hurt_, Mar 13 2016
%t PowerMod[5, Range[0, 50], 22] (* _G. C. Greubel_, Mar 13 2016 *)
%t PadRight[{},120,{1,5,3,15,9}] (* _Harvey P. Dale_, Sep 30 2019 *)
%o (Sage) [power_mod(5,n,22) for n in range(0,94)] # _Zerinvary Lajos_, Nov 26 2009
%o (PARI) a(n)=lift(Mod(5,22)^n) \\ _Charles R Greathouse IV_, Mar 22 2016
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, May 12 2002
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