Composite Magic Squares
Composite magic sqaures are magic squares that exist out of other magic
squares. As a 3 by 3 magic square is the smallest possible magic square,
it would be a fair guess to think that an order 6 magic square could be a
composite magic square, however, this is not the case. Consider a 3 by 3
magic square consisting of numers 1 through 9 and giving it the number 1,
an order 3 magic square consisting of numbers 10 through 18 => 2, 19
through 27 => 3 and 28 through 36 => 4. Than from these numbers 1 through
4, it becomes impossible to create a magic square, as an order 2 magic
square can not exist (only 4 digits to use). Therefore, the first possible
composite magic square is of order 9, as 9 order 3 magic squares can exist
inside of it. An order 12 magic square can be composite in two ways, it
can consist out of 12 order 3 magic squares, or 9 order 4 magic squares.