A275117 Direction where Langton's ant is looking after n moves: 1 if looking in starting direction, 2 if looking 90 degrees clockwise from starting direction, 3 if looking 90 degrees counterclockwise from starting direction, or 4 if looking in direction opposite to starting direction.

1, 2, 4, 3, 1, 3, 1, 2, 4, 3, 4, 3, 1, 2, 4, 2, 1, 3, 4, 3, 4, 3, 1, 2, 4, 2, 4, 3, 1, 2, 1, 3, 4, 2, 4, 2, 4, 3, 1, 2, 1, 2, 4, 3, 1, 3, 4, 2, 1, 2, 1, 3, 1, 2, 1, 2, 4, 3, 1, 3, 4, 2, 1, 2, 1, 2, 4, 3, 1, 3, 1, 2, 4, 3, 4, 2, 1, 3, 1, 3, 1, 2, 4, 3, 4, 3, 1

Offset: 0

Author

Felix Fröhlich, Jul 18 2016

Keywords

• nonn

Crossrefs

Cf. A102358, A102369, A204810, A255938, A261990, A269757.

Formula

From Andrey Zabolotskiy, Oct 11 2016: (Start)

Let d(n) = (A255938(n) mod 4). Then:

a(n)=1 if d(n)=0,

a(n)=2 if d(n)=1,

a(n)=4 if d(n)=2,

a(n)=3 if d(n)=3.

(End)

Extensions

More terms from Andrey Zabolotskiy, Oct 11 2016