The generator matrix

 1  0  0  1  1  1  1  1 35  1  1  1  1  1  1  1  1  1  1  1  1  1 14  1  7  1  1  1  1  1  1
 0  1  0 36 31 16 35 17  1  1 30 21  8 23 38 34 48 20  6  7 29  3  1 25  1 12 44  4 45 13  0
 0  0  1  5 31 34 36  4 16 25  1 38  9 47 35 43 10 40 42 41 21 20  4 46 38 40 48 12 32 34  7

generates a code of length 31 over Z49 who´s minimum homogenous weight is 171.

Homogenous weight enumerator: w(x)=1x^0+1260x^171+252x^174+942x^175+2268x^176+6048x^177+7098x^178+588x^180+3024x^181+4584x^182+6048x^183+9954x^184+12012x^185+2058x^186+3528x^187+9072x^188+9126x^189+10206x^190+14868x^191+14616x^192+42x^196+36x^203+12x^210+6x^217

The gray image is a code over GF(7) with n=217, k=6 and d=171.
This code was found by Heurico 1.16 in 2.13 seconds.