 Figure 1: Normal magic square. Image courtesy Sam Ley, St Louis, Missouri. 

A magic square is a square matrix containing numbers
such that the sum of any row,
column, or diagonal is the same^{[1][2]}. A magic square using the sequential numbers 1..n where
n is the number of cells is called a normal magic square.
Magic squares are believed to have been discovered
in China about 4^{th} century BCE. The 3x3 normal magic square was called
'Lo Shu' by the Chinese. Magic squares were known in ancient Egypt, India, and Arabia.
