1. The problem statement, all variables and given/known data If you have a square and can paint each side with one of three different colours, how many completely different arrays can you get? (rotated squares don't count) 2. Relevant equations 3. The attempt at a solution I was thinking 3^4 / 4 but, that is not an integer, (3^4 - 1) / 4 is an integer but why would you substract 1?