The generator matrix

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

generates a code of length 75 over Z4[X]/(X^2+2,2X) who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+52x^68+236x^69+219x^70+440x^71+270x^72+518x^73+317x^74+452x^75+219x^76+332x^77+204x^78+242x^79+102x^80+152x^81+75x^82+130x^83+51x^84+40x^85+12x^86+14x^87+7x^88+2x^89+4x^90+2x^91+2x^92+1x^94

The gray image is a code over GF(2) with n=300, k=12 and d=136.
This code was found by Heurico 1.16 in 1.01 seconds.