Simplifying cohort analysis formula in 1 row

[Yookii]

Hi All

I am trying to simplify a cohort analysis that requires multiple steps and formula into 1 row.

1. There are new users coming in particular month (row 3)
2. Every time you have new users, each cohort will decay at y = x^(-1) with y the new cohort intake and x the number of months (row 5-7)
3. I add all the decay together to get to the total (row 8).

Can you help me find a formula in row 10 that replaces total into a formula that fits into one row as opposed to having to create multiple rows for each new cohort intake? ie a formula that only uses row 1 and 3.
The formula needs to be the same from B10 to M10. A formula in B10 that I can drag to M10.


Many thanks
Yooki

Book1.xlsxScreenshot 2024-03-07 105252.png