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 A083054 #11 May 09 2014 12:20:07
%S A083054 1,0,2,0,2,1,0,1,0,2,1,2,1,0,1,0,2,1,2,1,0,2,0,2,1,0,1,0,2,0,2,1,0,1,
%T A083054 0,2,1,2,1,0,2,0,2,1,2,1,0,2,0,2,1,0,1,0,2,0,2,1,0,1,0,2,1,2,1,0,2,0,
%U A083054 2,1,2,1,0,2,0,2,1,0,1,0,2,1,2,1,0,1,0,2,1,2,1,0,2,0,2,1,0,1,0,2,0,2,1,0,1
%N A083054 a(n) = floor(sqrt(3)*n) - 3*floor(n/sqrt(3)).
%H A083054 Boris Gourevitch, <a href="http://membres.lycos.fr/bgourevitch/temporaires/benoit/sqrt3fractal.jpg">Graph of A083057</a>
%F A083054 a(n) = floor(n*sqrt(3)) mod 3. - _T. D. Noe_, Oct 11 2006
%o A083054 (PARI) {a(n)=if(n<1, 0, sqrtint(3*n^2)-3*sqrtint(n^2\3))} /* _Michael Somos_, Aug 31 2006 */
%Y A083054 Cf. A083035, A083038, A083055, A083056, A083057.
%Y A083054 Cf. A022383 (floor(n*sqrt(3))).
%K A083054 nonn
%O A083054 1,3
%A A083054 _Benoit Cloitre_, Apr 18 2003