Editing Magic square (section)

===Moment of inertia===
The ''moment of inertia'' of a magic square has been defined as the sum over all cells of the number in the cell times the squared distance from the center of the cell to the center of the square; here the unit of measurement is the width of one cell.<ref name=Loly/> (Thus for example a corner cell of a 3×3 square has a distance of <math>\sqrt{2},</math> a non-corner edge cell has a distance of 1, and the center cell has a distance of 0.) Then all magic squares of a given order have the same moment of inertia as each other. For the order-3 case the moment of inertia is always 60, while for the order-4 case the moment of inertia is always 340. In general, for the ''n''×''n'' case the moment of inertia is <math>n^2(n^4-1)/12.</math><ref name=Loly/>