need help in c++ program

[asra]

Hi everyone..
i am having trouble in making a logic of the following series, help me out!

i need to compute the sum of the following series
1-5/3+9/5-13/7+17/9-....up to n term(enter by user) using loops.

thanks in advance!

[Moschops]

The top number starts at 1 and goes up by 4 each time.

The bottom number starts at 1 and goes up by 2 each time.

So are you now able to generate the complete list of n terms?