# Revision history [back]

Trying to find them using brute force isn't that bad. The following worked for me

import itertools
Z9=Zmod(9)
I=Matrix(Z9,[[1,0],[0,1]])
L=[]
for a,b,c,d in itertools.product(Z9,repeat=4):
M=Matrix(Z9,[[a,b],[c,d]])
if I==M^3:
L.append(M)


The length of the list seems to be 297 though, but the 39th element seems to be the one that was missing from your list.