Cálculo de diferencias de elementos posteriores de una secuencia en F#

I have a sequence of floats in F#, and I need to get a sequence defined of (Math.Log currentElement)/(Math.Log previousElement). Obviously it will be shorter than the original sequence by one element.

What is the most elegant way to achieve this in F#? I was thinking to use a seq{} expression with a for loop inside, but even then handling the first element in a reasonably nice way seems difficult...