求 1+2!+3!+...+20!的和
summation = 1
for item_number in range(2, 21):
integer_product = 1
for integer in range(2, item_number+1):
integer_product *= integer
summation += integer_product
print(summation)
summation = 1
for item_number in range(2, 21):
integer_product = 1
for integer in range(2, item_number+1):
integer_product *= integer
summation += integer_product
print(summation)