Question 122
Three $n \times n$ squares form the figure $\Phi$ on the checkered plane as
shown in the picture. (Neighbouring squares touch along a segment of length $1$.)
Find all $n \gt 1$ for which the figure $\Phi$ can be covered with $1 \times 3$ and $3 \times 1$ tiles without overlapping.
shown in the picture. (Neighbouring squares touch along a segment of length $1$.)
Find all $n \gt 1$ for which the figure $\Phi$ can be covered with $1 \times 3$ and $3 \times 1$ tiles without overlapping.