Consider the following numbers (where n! is factorial(n)):
u1 = (1 / 1!) * (1!)
u2 = (1 / 2!) * (1! + 2!)
u3 = (1 / 3!) * (1! + 2! + 3!)
un = (1 / n!) * (1! + 2! + 3! + ... + n!)
Which will win: 1 / n! or (1! + 2! + 3! + ... + n!)?
Are these numbers going to 0 because of 1/n! or to infinity due to the sum of factorials?
Task
Calculate (1 / n!) * (1! + 2! + 3! + ... + n!) for a given n, where n is an integer greater or equal to 1.
To avoid discussions about rounding, return the result truncated to 6 decimal places, for example:
1.0000989217538616 will be truncated to 1.000098
1.2125000000000001 will be truncated to 1.2125
我的解法:
def going(n):
nnn=1
sum=0
for i in range(1,n+1):
nnn*=i
sum+=nnn
return (1/nnn)*sum