Decomino

[1] When rotations and reflections are not considered to be distinct shapes, there are 4,655 different free decominoes (the free decominoes comprise 195 with holes and 4,460 without holes).

When reflections are considered distinct, there are 9,189 one-sided decominoes.

[2] The 4,655 free decominoes can be classified according to their symmetry groups:[2] Unlike both octominoes and nonominoes, no decomino has rotational symmetry of order 4.

The 4,460 decominos without holes comprise 44,600 unit squares.

Such a square containing 4,410 decominoes was constructed by Livio Zucca.

The unique decomino with two axes of reflection symmetry, both aligned with the diagonals
A self-tiling tile set consisting of decominoes
A geometric magic square consisting of decominoes