On the spectra of the duals of binary BCH codes of designed distance delta =9

Abstract

An infinite series of duals of binary BCH codes with designed distance delta =9 and lengths l=2/sup n/ with n odd is found, such that their weights almost satisfy the Carlitz-Uchiyama bound. This solves negatively a problem formulated by F.J. MacWilliams and N.J.A. Sloane (1977).< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>