The generator matrix

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

generates a code of length 95 over GR(64,4) who´s minimum homogenous weight is 646.

Homogenous weight enumerator: w(x)=1x^0+5712x^646+5264x^647+231x^648+1904x^649+1512x^650+2464x^651+1232x^652+3472x^653+20552x^654+14952x^655+1932x^656+4480x^657+4928x^658+6608x^659+2128x^660+5264x^661+26264x^662+17808x^663+2492x^664+6832x^665+5768x^666+6272x^667+1904x^668+5936x^669+26040x^670+17640x^671+2870x^672+8288x^673+5712x^674+6160x^675+1904x^676+3248x^677+21784x^678+12432x^679+42x^680+35x^688+42x^696+14x^704+14x^712+7x^728

The gray image is a code over GF(8) with n=760, k=6 and d=646.
This code was found by Heurico 1.16 in 19.9 seconds.