I am trying to compute an equation x = (a/(1+r)^1) + (a/(1+r)^2) + (a/(1+r)^3) ... (to infinity); (or to some point like ... +(a/(1+r)^10)
How to input those dots which matheamtica can understand?
Also, how can it, using same or somewhat similar technique understand the input for some simpler expression like 1+3+5+7...+113 (which should be sum of first 114/2 odd numbers)
Thank you