Suppose $a_n = O(b_n)$ and also $b_n = O(a_n)$.
I want to express this but can't use $\Theta$ since it means something else in my report. I'm thinking about this $\approx$, but wondering if there is a better one.
I remember seeing a symbol like the $x$ rotated $90^0$, but don't know how it is called or the latex character.
Anyway, just want to hear your input.
Thank you!
A standard symbol for this is $\asymp$, as you said. To typeset it use
$\asymp$.If you know a symbol but not the command, use "Detexify", where you can draw symbols and are told the command.