For the recursive formula, x n+1
​
=x n
​
+ (n+1)!
1
​
such that x 0
​
=1. Find x 3
​
and the closed-form formula for x n
​
. x 3
​
= 2
5
​
x n
​
=1+∑ i=1
n
​
i!
1
​
x n
​
=1+∑ i=1
n
​
i
1
​
x 3
​
= 3
8
​
x n
​
=∑ i=1
n
​
i!
1
​
x 3
​
= 24
41
​
​