Notation for a divergent series

Question

When something converge we use the notation $<\infty$. For example

For all $s$ $s.t$ $Re(s)>1$

$$\zeta(s)<\infty$$

Can we say the opposite for a divergent series? i.e.

$$\sum_{n=1}^\infty \frac{1}{n}> \infty$$ Or do we say that it is equal to infnity? The question I ask is what mathematical notaion you would put there to avoid saying out loud "harmonic series diverges".

I have a presentation tomorrow and I would like it to look professional but I don't want to make fool out of myself.

Answer 1

We write $$\sum_{n=1}^{\infty}{1/n}=\infty$$ to mean "the harmonic series diverges", for example.