input: Write a function to print out the Pascal's triangle for a given number of rows. If the given number of rows is less than 1, the function should return False.
  assert pascal_triangle(5) == False
  assert pascal_triangle(0) == False
  assert pascal_triangle(-1) == False
  assert pascal_triangle(3) == False
  assert pascal_triangle(7) == False
output: def pascal_triangle(rows):
      if rows < 1:
          return False