Diagram of Square-1 shapes
Diagram of Square-1 shapes
Blue: 6+2 corners. Used in method 1.
Red: 5+3 corners
Yellow: 4+4 corners. Sum 0 in method 2.
Green: 4+4 corners. Sum 2 in method 2.
Purple: 4+4 corners. Sum 1 or 3 in method 2. Has exactly one asymmetric layer.