The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2  1  2  2  2  1  1  1  2  2  2  2  2  1  1  1
 0  2  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2  2  2  2  2  2  2  0  2  0  0  2  2  2  2  2  2  2  2  0  2  2  2  2  0  2  2  2  2  2  0  2  0  0  2  0  0
 0  0  2  0  0  0  0  0  0  0  0  0  0  0  0  2  0  0  0  0  0  0  0  0  0  2  2  2  2  2  2  2  0  0  0  0  2  0  0  2  2  0  2  0  2  2  2  2  2  0  0  2  2  0  2  0  2  2  2  0  2  2  0  2  0  0  0  2  0  0  0  0  0
 0  0  0  2  0  0  0  0  0  0  0  0  0  0  0  2  0  0  0  0  2  2  2  2  2  2  2  0  0  2  0  0  2  2  2  0  2  2  2  0  0  0  0  2  2  0  2  0  0  2  2  2  2  2  2  2  2  0  0  0  0  0  2  0  0  0  0  0  2  2  0  0  0
 0  0  0  0  2  0  0  0  0  0  0  0  0  0  2  0  0  0  2  2  2  2  2  2  0  0  0  0  2  2  0  2  0  0  2  0  2  2  2  0  2  2  0  2  2  0  0  0  2  0  2  0  2  0  0  0  0  2  0  0  0  0  2  2  0  0  2  2  0  2  0  0  0
 0  0  0  0  0  2  0  0  0  0  0  0  0  0  2  0  2  2  2  2  2  2  0  2  2  0  2  2  2  0  0  0  2  2  2  2  2  0  2  0  0  2  0  0  0  2  0  2  0  2  2  0  2  2  2  0  0  0  0  2  0  0  2  2  2  2  2  2  2  2  0  0  0
 0  0  0  0  0  0  2  0  0  0  0  0  0  2  0  0  2  2  0  2  2  0  2  0  2  0  2  2  2  0  2  0  0  2  0  2  0  0  2  0  2  0  2  2  0  2  2  2  2  0  2  2  0  0  2  2  2  0  0  0  2  2  0  2  0  0  2  2  2  0  2  0  0
 0  0  0  0  0  0  0  2  0  0  0  0  0  2  0  0  0  2  2  2  2  0  2  2  0  2  0  2  0  2  0  0  0  0  0  2  2  0  0  2  2  2  0  0  0  2  0  0  2  2  2  0  0  2  0  0  2  2  0  2  2  2  2  0  0  2  0  2  2  2  2  0  0
 0  0  0  0  0  0  0  0  2  0  0  0  2  0  0  0  0  2  2  0  2  0  0  0  2  2  2  0  0  0  2  2  2  0  2  2  2  0  2  0  2  0  2  0  2  2  0  0  0  0  2  2  0  0  0  0  0  2  0  0  2  2  2  0  2  0  2  2  0  2  2  0  0
 0  0  0  0  0  0  0  0  0  2  0  0  2  0  0  0  2  0  0  2  0  2  0  0  2  0  0  0  0  2  2  2  0  0  2  2  2  0  0  0  0  0  2  2  2  0  2  2  0  2  2  0  2  2  0  0  2  2  0  2  0  0  2  0  2  0  2  2  0  2  2  2  2
 0  0  0  0  0  0  0  0  0  0  2  0  2  2  2  2  2  0  0  0  2  0  0  2  2  0  0  2  0  2  2  0  0  2  2  0  2  0  2  2  2  0  0  2  0  2  0  0  2  0  2  0  0  2  2  0  0  2  0  0  0  0  2  0  2  0  0  0  2  0  0  2  2
 0  0  0  0  0  0  0  0  0  0  0  2  2  2  2  2  0  0  2  2  2  2  2  0  2  0  2  0  0  0  0  0  2  2  2  2  0  2  0  0  0  0  2  0  2  0  0  0  2  2  0  2  0  2  0  2  0  2  2  0  0  0  2  0  2  2  0  0  0  0  2  0  0

generates a code of length 73 over Z4 who´s minimum homogenous weight is 56.

Homogenous weight enumerator: w(x)=1x^0+106x^56+345x^60+533x^64+72x^66+873x^68+672x^70+1642x^72+1008x^74+1350x^76+288x^78+636x^80+8x^82+390x^84+204x^88+49x^92+13x^96+1x^100+1x^128

The gray image is a code over GF(2) with n=146, k=13 and d=56.
This code was found by Heurico 1.16 in 35.5 seconds.