If N=2k>8 then there exist exactly [(kβ1)/2] pairwise nonequivalent
Z4β-linear Hadamard (N,2N,N/2)-codes and [(k+1)/2] pairwise nonequivalent
Z4β-linear extended perfect (N,2N/2N,4)-codes. A recurrent construction of
Z4β-linear Hadamard codes is given.Comment: 7p. WCC-200