
Bisymmetric matrix

In mathematics, a bisymmetric matrix is a square matrix that is symmetric about both of its main diagonals. More precisely, an "n" × "n" matrix "A" is bisymmetric if it satisfies both "A" = "AT" and "AJ" = "JA" where "J" is the "n" × "n" exchange matrix.
For example, any matrix of the form
is bisymmetric.