The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  0  1  1  1  X  1  1  1  1  1  X  1  1  1
 0  1  1  3 5X+2  6 5X+4  5  0  X  X 5X+1  6  5  3 5X+2 5X+4  1 X+5 5X+1 4X+2  1 X+6 X+3 4X+4 X+3 X+6  1 4X+2 X+2 3X
 0  0 5X 3X 6X  X 2X 3X  X 4X 2X 6X 5X 4X 2X  0  X 6X 5X 3X  X 5X  0 5X 6X 4X 4X 2X 3X 2X  X

generates a code of length 31 over Z7[X]/(X^2) who´s minimum homogenous weight is 175.

Homogenous weight enumerator: w(x)=1x^0+420x^175+756x^176+798x^177+2040x^182+2016x^183+1344x^184+4014x^189+3402x^190+1974x^191+18x^196+24x^217

The gray image is a linear code over GF(7) with n=217, k=5 and d=175.
This code was found by Heurico 1.16 in 0.051 seconds.