With one parameter

class PowerOfTwo:
    def __getitem__(self, i):
        return 2 ** i


power2 = PowerOfTwo()
p2 = power2[2]
# p2 is 4
p8 = power2[8]
# p8 is 256
p16 = power2[16]
# p16 is 65536

print(f"{p2 = }")
print(f"{p8 = }")
print(f"{p16 = }")