Predicate Form - Set Theory

Question

What is the predicate form for this set:

$$\left\{1, \frac12, \frac13, \frac14, \frac15,\cdots\right\}$$

I understand that the sequence is $a_n=\frac1n, n\ge1$ but how do I represent that in predicate form?

Answer 1

$$\left\{ x ~\middle|~ \frac 1 x \in \Bbb N \right\}$$