Sol Lewitt made several series of prints, some exploring variations of solids.
This series of prints include "boundary lines," which define the limit at which the solid may grow.
Ernst Haeckel. Biologist. Zoologist. Artist. Irregular symmetry dominates his work.
He idealizes natural forms in the same way that conceptual artists and mathematicians idealize geometry.
His drawings were published as a book, The Art Forms of Nature (that's a free download, by the way).
Thoughtfully organic for most of his creative life, Hundertwasser provides a good example of the power of permutations and combinations with his Good Morning City series of prints.
By varying color combinations Hundertwasser created an edition run of 10, 000, where each print is unique. 
You can see a good collection of the Good Morning City Project prints at The Gallery of Surrealism.
MC Escher. One of the most famous Dutch artists of the past century.
Escher made prints and woodcuts based upon symmetry, rotations, and translations. He often based his designs upon well-known polygons.
Escher would create tessellations and tile the plane of his pictures by repeating a common visual motif.
