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 A309241 #30 Nov 27 2020 13:15:20 %S A309241 0,1,2,3,4,3,4,5,6,7,8,9,8,9,10,11,12,11,12,13,14,15,16,15,14,13,12, %T A309241 11,10,11,10,9,8,7,8,9,10,11,12,13,12,13,14,13,12,13,14,15,16,15,14, %U A309241 15,14,13,14,15,14,15,16,17,18,17,18,19,20,21,22,21,20,21 %N A309241 Langton's ant on a rhombitrihexagonal tiling: number of black cells after n moves of the ant when starting on a hexagon. %C A309241 On a white hexagon, turn 60 degrees right, flip the color of the cell, then move forward one unit. %C A309241 On a black hexagon, turn 60 degrees left, flip the color of the cell, then move forward one unit. %C A309241 On a white square, turn 90 degrees right, flip the color of the cell, then move forward one unit. %C A309241 On a black square, turn 90 degrees left, flip the color of the cell, then move forward one unit. %C A309241 On a white triangle, turn 60 degrees right, flip the color of the cell, then move forward one unit. %C A309241 On a black triangle, turn 60 degrees left, flip the color of the cell, then move forward one unit. %H A309241 Lars Blomberg, <a href="/A309241/b309241.txt">Table of n, a(n) for n = 0..1000</a> %H A309241 Lars Blomberg, <a href="/A309241/a309241.png">The state for n=185, when 33 cells are set which is the maximum within the cycle</a> %H A309241 Lars Blomberg, <a href="/A309241/a309241.mp4">Animation illustrating n=1-1000</a> %H A309241 Felix Fröhlich, <a href="/A309241/a309241.pdf">Illustration of iterations 0-50</a>, 2019. %H A309241 Wikipedia, <a href="https://en.wikipedia.org/wiki/Langton%27s_ant">Langton's ant</a> %H A309241 Wikipedia, <a href="https://en.wikipedia.org/wiki/Rhombitrihexagonal_tiling">Rhombitrihexagonal tiling</a> %F A309241 a(n+448) = a(n). - _Lars Blomberg_, Aug 16 2019 %e A309241 See illustrations in Fröhlich, 2019. %Y A309241 Cf. A255938, A269757, A308590, A308937, A308973, A326167, A326352, A309064, A309166. %K A309241 nonn %O A309241 0,3 %A A309241 _Felix Fröhlich_, Jul 17 2019 %E A309241 More terms from _Lars Blomberg_, Aug 16 2019