Help calculating leads needed in a year by month

For the life of me, I can figure this out! Any help is much appreciated.

I know two variables:
- Monthly growth rate: 8%
- End of year target: 50

I need to calculate how many leads I need each month to hit that year end total. I know by figuring it out manually that the month one number is 2.635. It then grows by 8% per month and finishes in month 12 at 6.144. The sum of all 12 months ends up being 50, which is my target. But how can I calculate this so that if my growth rate or target change, the months are automatically recalculated?