input: Write a function to generate the first n prime numbers using the Sieve of Eratosthenes method. The function should return a list of the first n prime numbers. If n is less than or equal to 0, the function should return an empty list.
  def first_n_primes(n):
      if n <= 0:
          return []
      maximum = n * 10
      primes = [True] * maximum
      primes[0] = primes[1] = False
      for i in range(2, int(maximum**0.5)+1):
          if primes[i]:
              for j in range(i*i, maximum, i):
                  primes[j] = False
  
      prime_numbers = []
      for i in range(maximum):
          if primes[i]:
              prime_numbers.append(i)
          if len(prime_numbers) == n:
              break
      return prime_numbers
  assert first_n_primes(0) == []
  assert first_n_primes(1) == [2]
  assert first_n_primes(5) == [2, 3, 5, 7, 11]
  assert first_n_primes(10) == [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
output: def first_n_primes(n):
      if n <= 0:
          return []
      maximum = n * 10
      primes = [True] * maximum
      primes[0] = primes[1] = False
      for i in range(2, int(maximum**0.5)+1):
          if primes[i]:
              for j in range(i*i, maximum, i):
                  primes[j] = False
  
      prime_numbers = []
      for i in range(maximum):
          if primes[i]:
              prime_numbers.append(i)
          if len(prime_numbers) == n:
              break
      return prime_numbers