input: Write a function to calculate the Fibonacci numbers up to a given number. Return a list of Fibonacci numbers where the largest number does not exceed the given input number.
  def Fibonacci_sequence(n):
      sequence = []
      a, b = 0, 1
      while b <= n:
          sequence.append(b)
          a, b = b, a + b
      return sequence
  
  assert Fibonacci_sequence(0)==[]
  assert Fibonacci_sequence(1)==[1]
  assert Fibonacci_sequence(2)==[1, 2]
  assert Fibonacci_sequence(13)==[1, 2, 3, 5, 8, 13]
  assert Fibonacci_sequence(21)==[1, 2, 3, 5, 8, 13, 21]
output: def Fibonacci_sequence(n):
      sequence = []
      a, b = 0, 1
      while b <= n:
          sequence.append(b)
          a, b = b, a + b
      return sequence