MathDB

In the beginnig, each square of a strip formed by

n

adjacent squares contains

0

1

. At each step, we are writing

1

to the squares containing

0

and to the squares having exactly one neighbour containing

1

, and we are writing

0

s into the other squares.
Determine all possible values of

n

such that whatever the initial arrangement of

0

and

1

is, after finite number of steps, all squares can turn into

0

2