In my paper Tiling Rectangles and Half Strips with Congruent Polyominoes, I asked if the L polyomino of size n , where n ≡ 2 mod 4 , can tile a rectangle using an odd number of tiles. Philippe Rosselet has shown that the answer is "yes".
L6 tiles a 14 × 21 rectangle:
L10 tiles a 22 × 55 rectangle:
L14 tiles a 30 × 105 rectangle:
In general, L4m+2 tiles an (8m + 6) × (4m + 3)(2m + 1) rectangle.
Charles Jepsen has independently found a similar tiling, see [1, Figure 5].
Reference:
[1] Charles H. Jepsen, Lowell Vaughn and Daren Brantley,
Orders of L-shaped Polyominoes,
Journal of Recreational Mathematics 32 (2003-2004), no. 3,
pp. 226-231.