MathJax doesn't work on my site

I’m trying to get MathJax (https://www.mathjax.org/) to work on my WordPress 3.6.1 site. I’ve linked to the MathJax script using this script from their site:

<script type="text/javascript"
   src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
</script>

And I get no errors in my browser console, but for some reason, LaTeX code on my page, specifically, $\int\limits_{n=0}^{\infty}$, doesn’t render as prettyprinted math, rather just as the source code.

I’ve tried some of the bona fide WP plugins that have similar functionality, but most of the render math as a PNG rather than type, and the remainder have nonstandard notations.

Are there any additional steps to take? Is WordPress suppressing MathJax somehow?