How to express this sum concisely in R?

Question

I have a simple R beginner's question:

How do I express the sum below most concisely in R?

sum_{i=1}^n a / (a+i)

I tried the following, but there must be a better way, without actually calling for:

r<-0
for(i in 1:n){ r <- r + (a / (a+i)) }

Thanks!

Answer 1

I believe it's as simple as:

sum(a/(a+1:n))

Answer 2

You just do:

r <- sum(a/(a+1:n))