This was covered in MIT 6.042 in in a different and bit harder way by Tom Leighton as a general proof. The problem involved tiling the Stata courtyard with L-s

This was covered in MIT 6.042 in in a different and bit harder way by Tom Leighton as a general proof. The problem involved tiling the Stata courtyard with L-shaped tiles. You need a bit of mathematical induction to prove such results.