2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/142016We obtain, using exponential quadratic sums, explicit expressions for the number of double persymmetric matrices with entries in F_2 of given rank. (A matix [a(i,j)) is persymmetric if a(i,j) = a(r,s) for i+j = r+s)160 pagesNumber Theory11 T 23, 15 A 33text