Article : Tiling design - Colegiul National C. Negruzzi (Iași - Roumanie)

This work focuses on counting the number of different tiling designs that can be obtained on a rectangular grid, using three types of tiles: 1 x 1 squares, dominos and L-shaped trominos. For 2 x n grids, the authors consider tilings by dominos, or by dominos and 1 x 1 squares, or by triominos, dominos and 1 x 1 squares; they study also the number of tilings of a 3 x n grid by dominos. In each case they derive appropriate recurrence relations and they able to find the number of all possible tilings.