A070416 - OEIS

%I #37 Dec 27 2023 08:37:57

%S 1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,

%T 23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,

%U 17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23,1,7,17,23

%N a(n) = 7^n mod 32.

%H G. C. Greubel, <a href="/A070416/b070416.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,1).

%F From _R. J. Mathar_, Apr 20 2010: (Start)

%F a(n) = a(n-4).

%F G.f.: ( -1 - 7*x - 17*x^2 - 23*x^3 ) / ( (x-1)*(1+x)*(1+x^2) ). (End)

%F E.g.f.: 9*cosh(x) + 15*sinh(x) - 8*cos(x) - 8*sin(x). - _G. C. Greubel_, Mar 20 2016

%t PowerMod[7, Range[0, 50], 32] (* _G. C. Greubel_, Mar 20 2016 *)

%o (Sage) [power_mod(7,n,32)for n in range(0,84)] # _Zerinvary Lajos_, Nov 27 2009

%o (PARI) a(n) = lift(Mod(7, 32)^n); \\ _Altug Alkan_, Mar 20 2016

%o (Magma) [Modexp(7, n, 32): n in [0..100]]; // _Bruno Berselli_, Mar 22 2016

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, May 12 2002