The generator matrix

 1  0  0  1  1  1  0  1  1  2  1  2  1  2  1 X+2 X+2  X  1  1  1 X+2  1  1  0  X  0  1  1  1  1  1  1  1  1  1  1  0 X+2  1  0  0  1  1  X  1  2  1  1  2  1  X  1  1  1  1 X+2  2 X+2  1  1  1  1  1
 0  1  0  0  1  1  1  2  1  1  3  1  2  X X+3  1  2  1 X+2  1  X  1 X+1 X+1  2  1  1  X  2  2 X+1  X X+1 X+3  2  1 X+2  1  1  2  1  1  X  3  X X+3  1 X+3  1 X+2  2  1  1  1 X+3  3  X  1  X  X  3 X+1  X X+2
 0  0  1 X+1 X+3  0 X+1  X  1  3 X+2  X  3  1  0  2  1  3 X+3 X+3  2 X+3 X+1  X  1 X+2  X  3  2  0  3  3 X+2  3 X+2  0  2  0  3 X+1  1 X+1 X+1  X  1 X+2  1 X+3 X+3  1 X+1  0  2 X+2  2  2  1 X+3  1  0 X+2  1 X+3 X+3
 0  0  0  2  0  0  0  2  2  2  0  0  0  2  2  2  2  2  0  2  0  0  0  2  0  0  2  0  2  0  2  0  0  0  0  2  2  2  2  2  2  0  2  0  2  2  0  0  2  2  0  0  0  2  0  0  2  2  0  0  0  0  0  2
 0  0  0  0  2  0  2  0  2  2  2  2  0  0  2  2  2  0  2  0  2  0  0  0  2  2  0  2  0  2  0  0  2  2  0  0  0  2  0  0  0  2  2  0  0  0  0  2  2  0  2  2  0  2  0  2  2  2  0  2  2  0  0  2
 0  0  0  0  0  2  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2  2  2  2  2  2  0  0  2  0  0  2  2  2  2  0  2  2  0  2  2  2  2  0  0  0  0  0  2  2  2  0  0  2  2  0  0  0  2  0  2  0  0  0

generates a code of length 64 over Z4[X]/(X^2+2,2X) who´s minimum homogenous weight is 58.

Homogenous weight enumerator: w(x)=1x^0+171x^58+212x^59+452x^60+376x^61+569x^62+248x^63+442x^64+256x^65+375x^66+160x^67+234x^68+184x^69+193x^70+72x^71+62x^72+16x^73+30x^74+12x^75+22x^76+6x^78+3x^80

The gray image is a code over GF(2) with n=256, k=12 and d=116.
This code was found by Heurico 1.16 in 1.06 seconds.