5x5 integer matrices with integer inverses.

I wrote the following code to randomly generate some 5x5 matrices whose inverses are integers. 

from numpy import *
for i in range(10000000):
    a=random.randint(-5,5,size=(5,5))
    if abs(round(linalg.det(a)*100))==100.0:
        b=array(around(linalg.inv(a)),dtype=int)
        if max(abs(b.flatten()))<11:
            print(a.__repr__())
            print(b.__repr__())

  Some of the resulting matrices and their inverses are: