Margalef's richness index:(S-1)/ln(n), whereSis the number of taxa, andnis the number of individuals.

Hi all, this may seem pretty simple to you all, but I admit that when it comes to numbers I struggle.

Please correct me where I (may) be getting this wrong:

[(S-1)/ln] x n = answer

My struggling point is, what is 'ln' I can't seem to find this anywhere (is it simply 1-n?).

Thanks for your help!