This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A070361 #33 Dec 25 2023 11:24:11
%S A070361 1,3,9,27,40,38,32,14,1,3,9,27,40,38,32,14,1,3,9,27,40,38,32,14,1,3,9,
%T A070361 27,40,38,32,14,1,3,9,27,40,38,32,14,1,3,9,27,40,38,32,14,1,3,9,27,40,
%U A070361 38,32,14,1,3,9,27,40,38,32,14,1,3,9,27,40,38,32,14,1,3,9,27,40,38,32
%N A070361 a(n) = 3^n mod 41.
%H A070361 G. C. Greubel, <a href="/A070361/b070361.txt">Table of n, a(n) for n = 0..1000</a>
%H A070361 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,-1,1).
%F A070361 G.f.: (1+2*x+6*x^2+18*x^3+14*x^4)/ ((1-x) * (1+x^4)). - _R. J. Mathar_, Mar 13 2010
%F A070361 a(n) = a(n-2)+a(n-6)-a(n-4). - _Vincenzo Librandi_, Feb 06 2011
%F A070361 a(n) = a(n-8). - _G. C. Greubel_, Mar 09 2016
%t A070361 PowerMod[3, Range[0,50], 41] (* or *) Table[Mod[3^n, 41], {n, 0, 100}] (* _G. C. Greubel_, Mar 09 2016 *)
%t A070361 LinearRecurrence[{1,0,0,-1,1},{1,3,9,27,40},100] (* _Harvey P. Dale_, Mar 27 2020 *)
%o A070361 (PARI) a(n)=lift(Mod(3,41)^n) \\ _Charles R Greathouse IV_, Mar 22 2016
%Y A070361 Cf. A000244.
%K A070361 nonn,easy
%O A070361 0,2
%A A070361 _N. J. A. Sloane_, May 12 2002