input: Write a function to generate a list comprehension that squares each element of the given list [1, 2, 3, 5, 8, 13]. The function should return the squared values in a list.
  assert squared_values([1, 2, 3, 5, 8, 13])==[1, 4, 9, 25, 64, 169]
output: def squared_values(lst):
      return [x**2 for x in lst]