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 A070350 #22 Dec 18 2023 14:23:38 %S A070350 1,2,4,8,16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38,31,17,34,23,1,2, %T A070350 4,8,16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38,31,17,34,23,1,2,4,8, %U A070350 16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38,31,17,34,23,1,2,4,8,16,32,19,38 %N A070350 a(n) = 2^n mod 45. %H A070350 G. C. Greubel, <a href="/A070350/b070350.txt">Table of n, a(n) for n = 0..1000</a> %H A070350 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1). %F A070350 From _R. J. Mathar_, Feb 06 2011: (Start) %F A070350 a(n) = a(n-12). %F A070350 G.f.: (-1-2*x-4*x^2-8*x^3-16*x^4-32*x^5-19*x^6-38*x^7-31*x^8 -17*x^9 -34*x^10-23*x^11 ) / ( (x-1)*(1+x+x^2)*(1+x)*(1-x+x^2)*(1+x^2)*(x^4-x^2+1) ). (End) %t A070350 PowerMod[2, Range[0, 50], 45] (* _G. C. Greubel_, Mar 11 2016 *) %o A070350 (PARI) a(n)=lift(Mod(2,45)^n) \\ _Charles R Greathouse IV_, Mar 22 2016 %o A070350 (GAP) List([0..79],n->PowerMod(2,n,45)); # _Muniru A Asiru_, Jan 30 2019 %K A070350 nonn,easy %O A070350 0,2 %A A070350 _N. J. A. Sloane_, May 12 2002