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1/(n*ln(n))

Sum of series 1/(n*ln(n))



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The solution

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  oo          
 ___          
 \  `         
  \      1    
   )  --------
  /   n*log(n)
 /__,         
n = 1         
n=11nlog(n)\sum_{n=1}^{\infty} \frac{1}{n \log{\left(n \right)}}
Sum(1/(n*log(n)), (n, 1, oo))
The radius of convergence of the power series
Given number:
1nlog(n)\frac{1}{n \log{\left(n \right)}}
It is a series of species
an(cxx0)dna_{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:
Rd=x0+limnanan+1cR^{d} = \frac{x_{0} + \lim_{n \to \infty} \left|{\frac{a_{n}}{a_{n + 1}}}\right|}{c}
In this case
an=1nlog(n)a_{n} = \frac{1}{n \log{\left(n \right)}}
and
x0=0x_{0} = 0
,
d=0d = 0
,
c=1c = 1
then
1=limn((n+1)log(n+1)1log(n)n)1 = \lim_{n \to \infty}\left(\frac{\left(n + 1\right) \log{\left(n + 1 \right)} \left|{\frac{1}{\log{\left(n \right)}}}\right|}{n}\right)
Let's take the limit
we find
True

False
The rate of convergence of the power series
-0.010-0.008-0.006-0.004-0.0020.0100.0000.0020.0040.0060.0080.00
Numerical answer [src]
Sum(1/(n*log(n)), (n, 1, oo))
Sum(1/(n*log(n)), (n, 1, oo))
The graph
Sum of series 1/(n*ln(n))

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