[math-fun] Magic Square Forms for Combinatorial Designs

Two items dealing with both magic squares and combinatorial designs. Two 4x4 squares containing every double from 1-16. http://demonstrations.wolfram.com/MagicSquaresAndDesigns/ Four 8x8 squares containing every double from 1-64. http://demonstrations.wolfram.com/The26481Design/ Similar constructions have been proven impossible for the 6x6, 10x10, 14x14, 22x22.  Existence of designs for 12x12,18x18, 20x20  are all unsolved problems, in square form or not. The designs behind a possible set of 16x16 squares exist, but I haven't mapped them to a magic square form.