Author(s)

Premalatha Junius, Viorel Nitica

Department of Mathematics, West Chester University, West Chester, PA, USA.

We show that the least number of cells (the gap number) one needs to take out from a rectangle with integer sides of length at least 2 in order to be tiled by ribbon right trominoes is less than or equal to 4. If the sides of the rectangle are of length at least 5, then the gap number is less than or equal to 3. We also show that for the family of rectangles that have nontrivial minimal number of gaps, with probability 1, the only obstructions to tiling appear from coloring invariants. This is in contrast to what happens for simply connected regions. For that class of regions Conway and Lagarias found a tiling invariant that does not follow from coloring.

Tiling Rectangles, Ribbon Tromino, Rectangle with Gaps, Gap Number, Coloring Invariants

Junius, P. and Nitica, V. (2017) Tiling Rectangles with Gaps by Ribbon Right Trominoes. Open Journal of Discrete Mathematics, 7, 87-102. doi: 10.4236/ojdm.2017.72010.