 Centrosymmetric matrix

In mathematics, especially in linear algebra and matrix theory, a centrosymmetric matrix is a matrix which is symmetric about its center.More precisely, an "n" × "n" matrix "A" = [ "A"i,j ] is centrosymmetric when its entries satisfy

If "J" denotes the "n" × "n" matrix with 1 on the counterdiagonal and 0 elsewhere (that is, "J"i,n+1-i = 1; "J"i,j = 0 if j ≠ n+1-i), then a matrix "A" is centrosymmetric if and only if "AJ = JA".