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 A070458 #17 Dec 18 2023 12:54:37
%S A070458 0,1,4,9,16,25,0,13,28,9,28,13,0,25,16,9,4,1,0,1,4,9,16,25,0,13,28,9,
%T A070458 28,13,0,25,16,9,4,1,0,1,4,9,16,25,0,13,28,9,28,13,0,25,16,9,4,1,0,1,
%U A070458 4,9,16,25,0,13,28,9,28,13,0,25,16,9,4,1,0,1,4,9,16,25,0,13,28,9,28,13,0
%N A070458 a(n) = n^2 mod 36.
%H A070458 G. C. Greubel, <a href="/A070458/b070458.txt">Table of n, a(n) for n = 0..1000</a>
%H A070458 <a href="/index/Rec#order_18">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, 1).
%F A070458 a(n) = a(n-18). - _G. C. Greubel_, Mar 25 2016
%t A070458 Table[Mod[n^2,36],{n,0,200}] (* _Vladimir Joseph Stephan Orlovsky_, Apr 27 2011 *)
%t A070458 PowerMod[Range[0,90],2,36] (* _Harvey P. Dale_, Jan 02 2016 *)
%o A070458 (PARI) a(n)=n^2%36 \\ _Charles R Greathouse IV_, Apr 06 2016
%Y A070458 Cf. A070456, A070457.
%K A070458 nonn,easy
%O A070458 0,3
%A A070458 _N. J. A. Sloane_, May 12 2002