OK, so we know that if the elements of a series converge to zero (for example a geometric series with r<1), then we can calculate the sum. But what if the formula for successive elements is not explicitly known?
Pic rel is a real-life sequence showing the (sorted) first 10 elements of a set. I know that the set has a finite size n > 10, and I want to somehow estimate the sum of all elements.
What would be the way to go about it? I was thinking to estimate it using some formula and tweak the parameters using least-squares, but what would be the appropriate formula?