input: Write a function to generate a Fibonacci sequence of the first n numbers. The function should take an integer n as input and return a list of the Fibonacci sequence. If n is less than or equal to 0, return an empty list. If n is 1, return a list with only the first Fibonacci number. If n is 2 or more, return a list with the first n Fibonacci numbers.
  assert FibonacciSequence(1) == [0]
  assert FibonacciSequence(2) == [0, 1]
  assert FibonacciSequence(5) == [0, 1, 1, 2, 3]
  assert FibonacciSequence(0) == []
  assert FibonacciSequence(-1) == []
output: def FibonacciSequence(n):
      if n <= 0:
          return []
      elif n == 1:
          return [0]
      elif n == 2:
          return [0, 1]
      else:
          fib_seq = [0, 1]
          for i in range(2, n):
              fib_seq.append(fib_seq[-1] + fib_seq[-2])
          return fib_seq