The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  X  X  1  1  1  1  X  X  X  1  1  X  X  X  2  2  2  1  X  1  X  X  X  X  1  X 2X 2X 2X  2  2  2  2  0  0  0
 0 2X  0 2X  0  0 2X 2X  0  0 2X 2X  0  0 2X 2X  0  0 2X 2X  0 2X 2X  0  0 2X 2X  0 2X 2X  0  0 2X 2X  0 2X 2X  0 2X  0 2X  0  0 2X 2X  0  0  0 2X 2X  0 2X 2X  0 2X 2X  0
 0  0 2X 2X  0 2X 2X  0  0 2X 2X  0  0 2X 2X  0  0 2X 2X  0 2X 2X  0  0 2X 2X  0 2X 2X  0  0 2X 2X  0 2X 2X  0 2X 2X  0  0  0 2X 2X  0  0  0 2X 2X  0 2X 2X  0  0  0 2X 2X

generates a code of length 57 over Z4[X]/(X^2+2) who´s minimum homogenous weight is 57.

Homogenous weight enumerator: w(x)=1x^0+32x^57+17x^58+8x^59+3x^60+3x^62

The gray image is a code over GF(2) with n=456, k=6 and d=228.
This code was found by Heurico 1.16 in 0.094 seconds.