So I have the following situation:
In the first column I have certain values, in the second column, given a certain row, I want it to contain the result of a function applied to all the preceeding rows (plus itself) in the 1st column. In this case the function applied is
The dumb approach is the one I used: write the formula in the first row, then copy&paste down till the row you want the function to be applied to.
I want it to be automated, though, and function with as many rows in the given column as there are, even if they are removed or added. I thought I'd use
ARRAYFORMULA() for this, or
MMULT() combined with
TRANSPOSE() as I've seen doing in apparently related examples, but after quite a few tries I'm lost.
Does anybody know how it can be done?