J. Integer Seq. 20(5), Article 17.5.8, 15 p. (2017)
Summary
Summary: In this paper we give recursive formulas for the number of colorful tilings of small rectangular arrays. We enumerate the tilings of a $2 \times n$ board with painted squares, dominoes, and I-trominoes. We also provide a recursion formula for the number of tilings of a $3 \times n$ board with colorful squares and dominoes. Finally, we describe a general method for calculating the number of colorful tilings of an $m \times n$ board with squares and dominoes.