The generator matrix

 1  0  1  1  1  1  1  1  1  0  1  1  1  0  1  1  1  1  1  2  1  1 2a  1  1  0  1  1  1  1  1  1  1  1 2a+2  1  1  1  0  1  1  1  1  1  1 2a  1  1  1  1  1  1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2  1
 0  1  1  a 3a+3  0 2a+3 a+1  a  1  0 2a+3  a  1 a+1  2 a+1 a+2 2a+3  1 a+1  a  1  0 3a  1 2a+3 2a+1  a  2 a+1 3a+1 3a+2 2a+1  1 2a+1 2a+3 a+2  1 3a+1  2 a+3  2 2a+3  2  1 a+3  0  a a+3  1 2a+3  1  2 2a+2 2a  0  3 3a+2 2a+1 2a 2a+1 2a+1 a+3  1 a+3 a+3 2a+1 a+3  1  0
 0  0 2a+2  0  0  0  2  2  2  2  2  2 2a+2 2a+2 2a  2 2a 2a+2 2a+2  0 2a+2 2a+2 2a 2a+2 2a 2a 2a  2 2a+2  2  2 2a+2  0 2a  0  0 2a  0  2  2 2a  0 2a  0  2 2a+2  0 2a+2  0 2a 2a+2 2a  0 2a 2a+2  0 2a+2 2a+2 2a  0 2a  2  2  2  2  0 2a+2 2a+2  0  2  0
 0  0  0  2  0  2 2a+2  0  2 2a+2  2  0 2a 2a+2  0 2a+2  0  0 2a 2a  2  2 2a+2 2a+2  0 2a 2a  0 2a+2  0 2a 2a 2a+2  2 2a+2 2a 2a+2  2  0  2 2a  0 2a+2 2a 2a 2a 2a 2a+2 2a 2a  0  0  0 2a  2  2 2a  2  2  0  2 2a  0 2a+2  2 2a 2a  2 2a+2 2a+2  0
 0  0  0  0 2a+2 2a+2  2 2a+2 2a  0 2a+2  2  2 2a  2 2a 2a  2 2a+2 2a+2  0 2a+2 2a+2  2  0 2a+2  0 2a+2 2a+2 2a  2  0  0  0 2a  0  2 2a 2a 2a+2 2a 2a  0 2a+2 2a+2  2  2  0 2a+2  2  2 2a+2 2a  2 2a+2  0  0  0  2  2  0  2 2a  2  2  0 2a+2 2a+2  0 2a+2  2

generates a code of length 71 over GR(16,4) who´s minimum homogenous weight is 196.

Homogenous weight enumerator: w(x)=1x^0+42x^196+72x^197+120x^199+513x^200+156x^201+384x^203+1170x^204+444x^205+540x^207+1767x^208+516x^209+456x^211+1908x^212+600x^213+576x^215+2499x^216+612x^217+480x^219+1656x^220+492x^221+396x^223+483x^224+156x^225+120x^227+66x^228+24x^229+45x^232+30x^236+21x^240+24x^244+9x^248+6x^264

The gray image is a code over GF(4) with n=284, k=7 and d=196.
This code was found by Heurico 1.16 in 1.6 seconds.