bracketsequationsmathjax

I want to post something on math.stackexchange, but I have doubts about visual aspects of it. Take a look at

${n \choose \lfloor \frac{n}{2}\rfloor}$


or

${ {n} \choose \frac{n}{k}}$


It just doesn't look good. The "n" and "k" inside {n \choose k} that I use here are too close to each other (and a little disproportional). Can something be done with this? Or I must to manually invent something similar to {n \choose k} with brackets or other things?

Thank you for any advice 🙂

Edit:\ By "n" and "k" I don't literally mean the n,k, but the phrases they represent, the upper and lower component of {n \choose k}

Here's a comparison; note that you should always avoid fractions in one of the arguments to \binom (which is preferred over the infix \choose).

\documentclass{article}
\usepackage{amsmath}

\begin{document}

Text style: $\binom{n}{\lfloor \frac{n}{2}\rfloor}$

Display: $\displaystyle\binom{n}{\lfloor \frac{n}{2}\rfloor}$

Good

Text style: $\binom{n}{\lfloor n/2\rfloor}$

Display: $\displaystyle\binom{n}{\lfloor n/2\rfloor}$
\end{document}


You can immediately see that the two story fraction is wrong.

Here's the rendering by MathJax of the same input (at least, what I get on my machine):