input: Write a Python function to determine if the specified number exists in an unending sequence.
  assert is_Number_in_Sequence(1,7,3) == True
  assert is_Number_in_Sequence(1,-3,5) == False
  assert is_Number_in_Sequence(3,2,5) == False
output: def is_Number_in_Sequence(start, step, number):
      if step == 0:
          return start == number
      if (number - start) % step == 0 and (number - start) // step >= 0:
          return True
      return False