I saw your other double post. I agree with the response there.
You have been given an honest and correct answer,
However, I will give you a different answer.
The infinite series (sum) is:
Therefore, for large values of N we can use as an approximation of
Consider a similar example,
And consider a Riemann integral over some positive closed interval on the function . If we try to calculate this sum directly through the definition of the Riemann integral we will probably not be able to because the true values is the logarithmic function which is transendental.
The harmonic series, , is a very slowly divergent series.
The series converges rather rapidly.
If fact for N=100 the estimate is correct in the first two decimal places.
For N=1000 the estimate is correct in the first four decimal places.
What is you point?