Formula for the nth term of a sequence

I need to find a formula for the nth term in the sequence

$\frac{2}{3}, \frac{3}{5}, \frac{4}{7}, \frac{5}{9}, \frac{6}{11}$

I have tried the usual approach to find a formula. I first assumed that it was a geometric sequence, but it does not have a common ratio. It is also not an arithmetic sequence. I am at a complete loss on how to find a formula for this.