The MathJax people recently started allowing the script to be called from their server.
I added a new post to my blog including the code you have to paste in your template html to get MathJax functionality in Blogger. With the new code you don't need to have MathJax installed in your own server.
Hope it helps.
Basically you just need to copy the following code snippet to Blogger template between
For a detailed instruction or other options e.g. changing inline math delimiters, please follow this post.
An updated script command for Blogger is available at http://www.mathjax.org/docs/1.1/start.html, where they suggest using
For an example of a blog using it at Blogger, is my blog at http://mathjaxtest.blogspot.com. It works fairly well, but one problem is that when one posts a comment in reply, the MathJax script is not applied to the preview version of the comment, only to the published version of the comment. This makes it hard to use MathJax in comments, since there is no way to check to typos in equations. Does anyone know a way to fix this problem with comments?
This answer comes from Tex.Stackexchange:
Copy-past the following code
in the HTML of the Blogger template (Design→Edit HTML→Edit Template) between
The advantage of this code on the other answers here is that the Mathjax rendered is closer to the one practiced on the SE network (in particular with the
$). Also one may use macros (