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

0,2

Links

Table of n, a(n) for n=0..86.

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)

Crossrefs

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

Sequence in context: A070402 A125941 A347270 * A243141 A243207 A297003

Adjacent sequences: A275114 A275115 A275116 * A275118 A275119 A275120

Keyword

nonn

Author

Felix Fröhlich, Jul 18 2016

Extensions

More terms from Andrey Zabolotskiy, Oct 11 2016

Status

approved