I'm studying for my final and my teacher gave me a worksheet. I have two sequence problems I do not understand at all. If anyone could please help I'd appreciate it!

1. Find the sum of the sequence, note i=symbol for factorial, I couldn't find a factorial symbol :

((2n-1)i) / ((2n+1)i)

2. find sum of sequence (That's exactly how written, I have no idea...) :

2, -1/2 + 1/8 - ... 1/2048