[O][O][O] [O][O][O] [O][O][O]If any one of these buttons is pressed, it and all of its directly adjacent neighbors will toggle their status on/off. (Diagonals do not change.)
The goal is to get all of the lights to be off. Which buttons must be pressed to accomplish this?
Which buttons would accomplish this goal in the minimum number of presses for 4x4, 5x5, 6x6, 7x7, 8x8, and 9x9 arrays?
A nice site with the game from 3 x 3 up to 8 x 8 is here.