On the Automorphism Groups of the Z2Z4-Linear 1-Perfect and   Preparata-Like Codes
  We consider the symmetry group of a $Z_2Z_4$-linear code with parameters of a $1$-perfect, extended $1$-perfect, or Preparata-like code. We show that, provided the code length is greater than $16$, this group consists only of symmetries that preserve the $Z_2Z_4$ structure. We find the orders of the symmetry groups of the $Z_2Z_4$-linear (extended) $1$-perfect codes. Keywords: additive codes, $Z_2Z_4$-linear codes, $1$-perfect codes, Preparata-like codes, automorphism group, symmetry group. 
Denis Krotov (Sobolev Institute of Mathematics, Novosibirsk, Russia)
cs.IT cs.DM math.CO math.IT