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 A326695 #9 Jul 20 2019 11:04:38 %S A326695 0,0,0,1,0,0,0,2,1,1,1,0,1,1,1,1,2,2,0,0,2,1,1,0,2,1,2,2,0,2,1,0,0,2, %T A326695 1,1,2,2,0,0,0,0,1,0,0,0,2,1,1,1,0,1,1,1,1,2,2,0,2,1,0,2,1,2,2,0,0,2, %U A326695 1,1,0,0,2,1,1,2,2,0,2,1,0,2,1,2,2,0,0 %N A326695 Langton's ant with three cell colors: color of the cell the ant moves to at the end of iteration n: 0 for white, 1 for black, 2 for gray. %C A326695 On a white square, turn 90 degrees right, change the color to black, then move forward one unit. %C A326695 On a black square, turn 90 degrees left, change the color to gray, then move forward one unit. %C A326695 On a gray square, turn 180 degrees, change the color to white, then move forward one unit. %H A326695 Felix Fröhlich, <a href="/A326693/a326693.pdf">Illustration of iterations 0-50</a>, 2019. %F A326695 a(n+276) = a(n). - _Rémy Sigrist_, Jul 20 2019 %e A326695 See illustrations in Fröhlich, 2019. %Y A326695 Cf. A261990, A326693, A326694. %K A326695 nonn %O A326695 0,8 %A A326695 _Felix Fröhlich_, Jul 19 2019 %E A326695 More terms from _Rémy Sigrist_, Jul 20 2019