I'm using a formula to calculate the sum of a geometric list but no matter what I do it never gives me the right output.

Question

The formula is:
x=2,4,8,16
n1=first value
nn=last value
Sx=n1-(n1*r**nn)/1-r

Does anyone knows why the output is never right??

Answer 1

Could you post an actual code sample? It's not easy to understand what...

x=2,4,8,16
n1=first value
nn=last value

...means. Is x a list of values and n1 the first value and nn the last value of this list?

Answer 2

https://code.sololearn.com/cBDr25PsEJK2/?ref=app

Answer 3

Is this code but the problem is in line 60