input: Write a python function to generate a Fibonacci sequence up to n numbers.
  assert generate_fibonacci_sequence(5) == [0, 1, 1, 2, 3]
  assert generate_fibonacci_sequence(8) == [0, 1, 1, 2, 3, 5, 8, 13]
  assert generate_fibonacci_sequence(1) == [0]
output: def generate_fibonacci_sequence(n):
      if n <= 0:
          return []
      sequence = [0] 
      if n > 1:
          sequence.append(1)
      for _ in range(2, n):
          sequence.append(sequence[-1] + sequence[-2])
      return sequence