






def 							A     (       a_					)     ->						list[int]:

					if length <= 0 or not isinstance(a_							,a_					):
										raise ValueError('Length must be a positive integer.'					)
					return [n * (2 * n - 1) for n in range(a_					)]


if __name__ == "__main__":
							print(hexagonal_numbers(length=5))
							print(hexagonal_numbers(length=10))








'''simple docstring'''







def  _lowerCamelCase				( lowercase						:      int						)	->	bool:
				if num < 0:
								return False

				_a								= num
				_a								= 0
				while num > 0:
								_a								= rev_num * 10 + (num % 10)
								num //= 10

				return num_copy == rev_num


if __name__ == "__main__":
					import doctest

					doctest.testmod()
