How to solve nchoosek(k,n), when k <=n?

[syedshan]

Hi all,

I was reading a research paper and trying to dig deep. The authors, at one point, have come to a formula as below.
Now, if n>k it is piece of cake to solve, but since k<=n it is not that easy for me. Any help would be appreciated in solving this.
Especially how I can solve in Matlab.

For reference, the actual equation is below.enter image description here

 

[albbg]

Your question is not clear for me.
It seems you have problems if n=k, is it correct ?
However in this case the argument of the summation is (-1)^n/n, since the binomial coefficient C(n,n)=1

 

[CataM]

This is a weird question.

"k" at some point will be equal to "n" because it goes from 1 to n... like it or not. The statement n>k or n=>k is useless.. simply due to the definition of the summation.