%I #22 Dec 18 2023 14:22:32
%S 1,2,4,8,16,32,17,34,21,42,37,27,7,14,28,9,18,36,25,3,6,12,24,1,2,4,8,
%T 16,32,17,34,21,42,37,27,7,14,28,9,18,36,25,3,6,12,24,1,2,4,8,16,32,
%U 17,34,21,42,37,27,7,14,28,9,18,36,25,3,6,12,24,1,2,4,8,16,32,17,34,21,42,37,27
%N a(n) = 2^n mod 47.
%H G. C. Greubel, <a href="/A070351/b070351.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_23">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 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-23).
%F G.f.: (-1-2*x-4*x^2-8*x^3-16*x^4-32*x^5 -17*x^6-34*x^7 -21*x^8-42*x^9 -37*x^10-27*x^11-7*x^12-14*x^13 -28*x^14-9*x^15 -18*x^16-36*x^17 -25*x^18-3*x^19 -6*x^20-12*x^21-24*x^22 ) / ( (x-1)*(1+x+x^2 +x^3+x^4+x^5 +x^6+x^7+x^8 +x^9+x^10+x^11 +x^12+x^13+x^14 +x^15+x^16+x^17 +x^18+x^19+x^20+x^21+x^22) ). (End)
%t PowerMod[2, Range[0, 50], 47] (* _G. C. Greubel_, Mar 11 2016 *)
%o (PARI) a(n)=lift(Mod(2,47)^n) \\ _Charles R Greathouse IV_, Mar 22 2016
%o (GAP) a:=List([0..100],n->PowerMod(2,n,47));; Print(a); # _Muniru A Asiru_, Jan 28 2019
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, May 12 2002