Counting dimer tilings
A dimer is a 2×1 domino-shaped rectangle. How many ways are there to arrange four non-overlapping dimers on a 3×3 grid, leaving one of the 9 spaces empty? The three essentially different ways to do t…
A dimer is a 2×1 domino-shaped rectangle. How many ways are there to arrange four non-overlapping dimers on a 3×3 grid, leaving one of the 9 spaces empty? The three essentially different ways to do t…