input: Write a function to calculate the sum of an exponential series given a base value \( x \) and the number of terms \( n \). The function should return the sum of the series from \( x^0 \) to \( x^n \). If the given number of terms \( n \) is 0, the function should return 1.
  
  def exponential_series(x, n):
      sum = 0
      for i in range(n + 1):
          sum += x ** i
      return sum
  
  assert exponential_series(2, 3) == 15
  assert exponential_series(3, 2) == 13
  assert exponential_series(1, 4) == 5
  assert exponential_series(0, 5) == 1
  assert exponential_series(5, 0) == 1
output: def exponential_series(x, n):
      sum = 0
      for i in range(n + 1):
          sum += x ** i
      return sum