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 A070448 #23 Dec 18 2023 13:51:36
%S A070448 0,1,4,9,16,25,10,23,12,3,22,17,14,13,14,17,22,3,12,23,10,25,16,9,4,1,
%T A070448 0,1,4,9,16,25,10,23,12,3,22,17,14,13,14,17,22,3,12,23,10,25,16,9,4,1,
%U A070448 0,1,4,9,16,25,10,23,12,3,22,17,14,13,14,17,22,3,12,23,10,25,16,9,4,1
%N A070448 a(n) = n^2 mod 26.
%H A070448 G. C. Greubel, <a href="/A070448/b070448.txt">Table of n, a(n) for n = 0..1000</a>
%H A070448 <a href="/index/Rec#order_26">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, 0, 0, 0, 0, 0, 0, 0, 0, 1).
%F A070448 G.f.: (x +4*x^2 +9*x^3 +16*x^4 +25*x^5 +10*x^6 +23*x^7 +12*x^8 +3*x^9 +22*x^10 +17*x^11 +14*x^12 +13*x^13 +14*x^14 +17*x^15 + 22*x^16 + 3*x^17 +12*x^18 +23*x^19 +10*x^20 +25*x^21 +16*x^22 +9*x^23 +4*x^24 +x^25)/(1-x^26). - _Vincenzo Librandi_, Dec 16 2014
%F A070448 a(n) = a(n-26). - _G. C. Greubel_, Mar 24 2016
%p A070448 A070448:=n->n^2 mod 26: seq(A070448(n), n=0..150); # _Wesley Ivan Hurt_, Apr 09 2017
%t A070448 Table[Mod[n^2,26],{n,0,200}] (* _Vladimir Joseph Stephan Orlovsky_, Apr 23 2011 *)
%t A070448 PowerMod[Range[0,80],2,26] (* _Harvey P. Dale_, Dec 15 2014 *)
%o A070448 (PARI) a(n)=n^2%26 \\ _Charles R Greathouse IV_, Apr 06 2016
%K A070448 nonn,easy
%O A070448 0,3
%A A070448 _N. J. A. Sloane_, May 12 2002