%I #14 Jan 26 2020 01:07:15

%S 0,1,2,3,4,3,4,5,6,6,5,4,3,4,3,2,1,0,0,0,1,2,2,1,0,1,1,0,0,0,1,1,0,1,

%T 2,2,1,0,0,0,1,2,3,4,3,4,5,6,6,5,4,3,4,3,2,1,0,0,0,1,1,0,1,1,0,0,0,1,

%U 2,2,1,0,1,2,2,1,0,0,0,1,1,0,1,1,0,0,0

%N Langton's ant with three cell colors: number of black cells after n moves of the ant.

%C On a white square, turn 90 degrees right, change the color to black, then move forward one unit.

%C On a black square, turn 90 degrees left, change the color to gray, then move forward one unit.

%C On a gray square, turn 180 degrees, change the color to white, then move forward one unit.

%C The complete configuration, including the position and direction of the ant and the color of all cells, has period 276. - _Rémy Sigrist_, Jul 19 2019

%H Felix Fröhlich, <a href="/A326693/a326693.pdf">Illustration of iterations 0-50</a>, 2019.

%F a(n+276) = a(n). - _Rémy Sigrist_, Jul 19 2019

%e See illustrations in Fröhlich, 2019.

%Y Cf. A325953, A325954, A325955, A326694, A326695.

%K nonn

%O 0,3

%A _Felix Fröhlich_, Jul 19 2019

%E More terms from _Rémy Sigrist_, Jul 19 2019