The generator matrix

 1  0  0  0  1  1  1  1  1  1  1  1  1  X a*X  1  1  1  1  1  1
 0  1  0  0  0  X  X a^2*X+1  a  1 a*X+1 X+1 a^2*X+a  X  1 X+a^2 a^2*X+a^2 a^2*X+1 a*X+a^2 a^2*X+a  0
 0  0  1  0  1 a^2*X+a a^2*X+a^2  a  a a^2 a^2*X a^2*X+a a^2  1 a^2*X+a^2 X+a a*X+a  1  X a*X+a  X
 0  0  0  1 a^2  a  1  0  X  X a^2*X+a  1 X+a  1 a^2*X a^2  0 a^2*X+1 a*X+1 X+1  X
 0  0  0  0  X  0 a*X a^2*X a*X  X a^2*X  X  0 a^2*X a^2*X  0  X a^2*X a^2*X a^2*X a^2*X

generates a code of length 21 over F4[X]/(X^2) who´s minimum homogenous weight is 48.

Homogenous weight enumerator: w(x)=1x^0+210x^48+156x^49+180x^50+612x^51+2151x^52+2112x^53+1380x^54+3648x^55+8745x^56+6936x^57+4968x^58+12744x^59+27687x^60+19104x^61+10728x^62+24000x^63+45705x^64+23916x^65+10980x^66+18996x^67+22860x^68+9216x^69+2484x^70+1440x^71+1101x^72+51x^76+30x^80+3x^84

The gray image is a linear code over GF(4) with n=84, k=9 and d=48.
This code was found by Heurico 1.16 in 51.9 seconds.