

'''simple docstring'''






from math import factorial


def 		_A     (    A__ = 20      ):






 """simple docstring"""



 __lowercase							  = 2 * n  # middle entry of odd rows starting at row 3 is the solution for n = 1,
 # 2, 3,...
 __lowercase							  = n // 2

 return int(factorial(__snake_case      ) / (factorial(__snake_case      ) * factorial(n - k      ))      )


if __name__ == "__main__":
 import sys

 if len(sys.argv) == 1:
  print(solution(20))
 else:
  try:
   lowerCAmelCase__											=	int(sys.argv[1])
   print(solution(n))
  except ValueError:
   print('''Invalid entry - please enter a number.''')









"""simple docstring"""



def 						lowercase    (				__snake_case				: int = 1_0_0	):
		lowercase_ : str							       =   0
		lowercase_ : List[Any]							       =   0
		for i in range(1		,					n + 1	):
				sum_of_squares += i**2
				sum_of_ints += i
		return sum_of_ints**2 - sum_of_squares


if __name__ == "__main__":
						print(F"""{solution() = }""")



