MathDB

Determine all positive integers

a

and

b

such that each square on the

a\times b

board can be colored red, blue, or green such that each red square has exactly one blue neighbor and one green neighbor, each blue square has exactly one red and one green neighbor and each green square has exactly one red and one blue neighbor.
Clarification: Two squares are neighbors if they have a common side.

4

Problems(1)