Question 161
We have an $n \times n$-board with $n \ge 3$ of which each square can be coloured white or black separately. Each move we change the colour of five chosen squares in the possibly rotated version of the following pentomino pattern.
At the beginning, all the squares are white. Determine for which $n$ it is possible to make all squares black after a finite number of moves.
At the beginning, all the squares are white. Determine for which $n$ it is possible to make all squares black after a finite number of moves.