An orthosymmetric matrix is a Hankel matrix in one usage of the term, with entries constant along each skew diagonal (Graham and Sloane 1984, p. 128). In another usage it is a persymmetric matrix symmetric under reflection about the skew diagonal (Petersen and Pedersen 2012, p. 54). Constancy along skew diagonals and reflection symmetry about the skew diagonal are different conditions.
Orthosymmetric Matrix
See also
Hankel Matrix, Persymmetric MatrixExplore with Wolfram|Alpha
References
Graham, R. L. and Sloane, N. J. A. "Anti-Hadamard Matrices." Lin. Algebra Appl. 62, 113-137, 1984. https://doi.org/10.1016/0024-3795(84)90090-9.Petersen, K. B. and Pedersen, M. S. "The Matrix Cookbook." Technical University of Denmark, p. 54, Nov. 15, 2012. https://www2.imm.dtu.dk/pubdb/edoc/imm3274.pdf.Referenced on Wolfram|Alpha
Orthosymmetric MatrixCite this as:
Weisstein, Eric W. "Orthosymmetric Matrix." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/OrthosymmetricMatrix.html