“…The research on multidiagonal, in particular tridiagonal and pentadiagonal matrices, intensified in the past years. These matrices have important applications in optimization problems [3], autoregression modelling [26], approximation theory [23], Gauss-Markov random processes [2], orthogonal polynomials, solving elliptic and parabolic PDE's with finite difference methods [10], inequalities (quadratic, Wirtinger, Opial's type) [4], [18].…”