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factorial(n)/((n*n))
Sum of series/ factorial(n)/((n*n))

Sum of series factorial(n)/((n*n))


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The solution

You have entered [src] 
  oo     
 ___     
 \  `    
  \    n!
   )  ---
  /   n*n
 /__,    
n = 1
$$\sum_{n=1}^{\infty} \frac{n!}{n n}$$ 
Sum(factorial(n)/((n*n)), (n, 1, oo))
The radius of convergence of the power series
Given number:
$$\frac{n!}{n n}$$
It is a series of species
$$a_{n} \left(c x - x_{0}\right)^{d n}$$
- power series.
The radius of convergence of a power series can be calculated by the formula:
$$R^{d} = \frac{x_{0} + \lim_{n \to \infty} \left|{\frac{a_{n}}{a_{n + 1}}}\right|}{c}$$
In this case
$$a_{n} = \frac{n!}{n^{2}}$$
and
$$x_{0} = 0$$
,
$$d = 0$$
,
$$c = 1$$
then
$$1 = \lim_{n \to \infty}\left(\frac{\left(n + 1\right)^{2} \left|{\frac{n!}{\left(n + 1\right)!}}\right|}{n^{2}}\right)$$
Let's take the limit
we find
False

False
The rate of convergence of the power series
The answer [src] 
  oo    
____    
\   `   
 \    n!
  \   --
  /    2
 /    n 
/___,   
n = 1
$$\sum_{n=1}^{\infty} \frac{n!}{n^{2}}$$ 
Sum(factorial(n)/n^2, (n, 1, oo))
Numerical answer
The series diverges
The graph
Sum of series factorial(n)/((n*n))

    Examples of finding the sum of a series

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