# Show a table of the squares of the first four numbers
print(" {:1s} | {:>3s} | {:>7s}".format("n", "n²", "2**n"))
for n in range(1, 21):
    print("{:2d} | {:3d} | {:7d}".format(n, n ** 2, 2 ** n))

# Modify the program to show the squares of 1..20.  (Use the range function.)
# Also, add a column to show 2**n.  Adjust the formatting.