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 A070436 #25 Jul 08 2024 21:42:50
%S A070436 0,1,4,9,3,12,10,10,12,3,9,4,1,0,1,4,9,3,12,10,10,12,3,9,4,1,0,1,4,9,
%T A070436 3,12,10,10,12,3,9,4,1,0,1,4,9,3,12,10,10,12,3,9,4,1,0,1,4,9,3,12,10,
%U A070436 10,12,3,9,4,1,0,1,4,9,3,12,10,10,12,3,9,4,1,0,1,4,9,3,12,10,10,12,3,9,4
%N A070436 a(n) = n^2 mod 13.
%H A070436 G. C. Greubel, <a href="/A070436/b070436.txt">Table of n, a(n) for n = 0..1000</a>
%H A070436 <a href="/index/Rec#order_13">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,0,0,0,0,1).
%F A070436 G.f.: (x^12 +4*x^11 +9*x^10 +3*x^9 +12*x^8 +10*x^7 +10*x^6 +12*x^5 +3*x^4 +9*x^3 +4*x^2 +x)/(-x^13 +1). - _Colin Barker_, Aug 14 2012
%F A070436 a(n) = a(n-13). - _G. C. Greubel_, Mar 24 2016
%t A070436 Table[Mod[n^2,13],{n,0,200}] (* _Vladimir Joseph Stephan Orlovsky_, Apr 21 2011 *)
%o A070436 (PARI) a(n)=n^2%13 \\ _Charles R Greathouse IV_, Apr 06 2016
%Y A070436 Cf. A070434, A070435.
%K A070436 nonn,easy
%O A070436 0,3
%A A070436 _N. J. A. Sloane_, May 12 2002