Dear all,

I have a tricky problem; I need to solve this equation for $\displaystyle N$

$\displaystyle \binom {L} {L-R}\sum_{r=1}^{R}\binom {R} {r} (-1)^{R-r}\left(\frac{r}{L}\right)^N\ln\frac{r}{L} =0

$

Is it possible in some way?

The only constraints are $\displaystyle R \leqslant L$, $\displaystyle R,L>0$

Thanks a lot

Simo