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%I #34 Jul 08 2022 01:57:10
%S 1,2,4,8,16,32,64,28,56,12,24,48,96,92,84,68,36,72,44,88,76,52,4,8,16,
%T 32,64,28,56,12,24,48,96,92,84,68,36,72,44,88,76,52,4,8,16,32,64,28,
%U 56,12,24,48,96,92,84,68,36,72,44,88,76,52,4,8,16,32,64,28
%N Final two digits of 2^n.
%C Has period 20 (starting with a(2)=4).
%H T. D. Noe, <a href="/A000855/b000855.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Fi#final">Index entries for sequences related to final digits of numbers</a>
%H <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,0,0,0,0,-1,1).
%F G.f.: -(50*x^12 +25*x^11 +13*x^10 -44*x^9 +28*x^8 -36*x^7 +32*x^6 +16*x^5 +8*x^4 +4*x^3 +2*x^2 +x +1) / ((x -1)*(x^2 +1)*(x^8 -x^6 +x^4 -x^2 +1)). - _Colin Barker_, Dec 01 2014
%t PowerMod[2,Range[0,60],100] (* _Harvey P. Dale_, Jan 05 2012 *)
%o (PARI) a(n)=lift(Mod(2,100)^n) \\ _Charles R Greathouse IV_, Dec 28 2012
%Y Cf. A000689, A126605.
%K nonn,base,easy
%O 0,2
%A _N. J. A. Sloane_
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