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 A054580 #19 Jul 02 2025 16:01:59
%S A054580 0,1,4,9,16,8,2,15,13,13,15,2,8,16,9,4,1,0,1,4,9,16,8,2,15,13,13,15,2,
%T A054580 8,16,9,4,1,0,1,4,9,16,8,2,15,13,13,15,2,8,16,9,4,1,0,1,4,9,16,8,2,15,
%U A054580 13,13,15,2,8,16,9,4,1,0,1,4,9,16,8,2,15,13,13,15,2,8,16,9,4,1,0,1,4,9
%N A054580 n^2 modulo 17.
%t A054580 Table[Mod[n^2,17],{n,0,200}] (* _Vladimir Joseph Stephan Orlovsky_, Apr 23 2011 *)
%t A054580 PowerMod[Range[0,90],2,17] (* _Harvey P. Dale_, Aug 16 2012 *)
%o A054580 (PARI) a(n)=n^2%17 \\ _Charles R Greathouse IV_, Apr 06 2016
%Y A054580 Cf. A070439, A070440, A070441.
%K A054580 nonn,easy
%O A054580 0,3
%A A054580 Stuart M. Ellerstein (ellerstein(AT)aol.com), Apr 11 2000
%E A054580 More terms from _James Sellers_, Apr 12 2000