Magic square is a square (N x N) matrix whose elements
are sequential integers (1,...,N2).
The matrix must satisfy the magic square condition:
Magic square condition:
"The summation of the elements of any column, row
or diagonal vectors has a unique value."
Such unique value is called "equi-sum" in this article.
What are magic cubes?
Magic cube is a N x N x N cube whose elements are sequential
integers (1, ..., N3). The magic cube is a natural
extension of a magic square toward three dimensional configuration
of the numbers. Magic cube must satisfy the magic square condition
for each existing plane. We call the third direction "pole" in this
article.