I suspect what you need is a call to the MathJax Typeset() method, as suggested in the following documentation page:
http://www.mathjax.org/docs/2.0/typeset.html
I'm not familiar with Blogger, so I don't know where to put the call, but you should be able to play around with it some. The key will be to make sure that Typeset is queued when (or after) the View is displayed.
When you do get this worked out, please post what you did, so that others can read about it in the future.