Simple Imperfect Squared Squared Squares; Orders 13 to 20

Perfect Squares can be derived from Imperfect Squares

Imperfect squared squares are both more numerous (at a given order) and less published than perfect squared squares.

SISS (Simple Imperfect Squared Squares) are by definition, imperfect, however it is possible to 'derive' SPSS (Simple Perfect Squared Squares) of order n-2 from SISS of order n. This also provides a means of verifying the SPSS counts obtained in lower orders.

Imperfection can result in symmetry

Some of these tilings have interesting symmetrical arrangements as a result of squares in the tiling being the same size.