If Harmonic Sequence
$ H_n=\left\{ {1,\frac{1}{2},\frac{1}{3},\frac{1}{4},\frac{1}{5},...} \right\} $
How can I find an arithmetic sequence using the above sequence?
Actually, I have found one by inspection. $ \left\{{\frac{1}{3},\frac{1}{4},\frac{1}{6}}\right\}\\ \text{It is an arithmetic sequence with common difference}=-\frac{1}{6} $ However, I have no idea on finding the other arithmetic sequence with more term. Thank you.