Where to publish short notes which don't deserve real publication (an article in a peer reviewed journal)?
I'd press it in blogs but even in blogs supporting math formulas (wordpress.com) it is not very convenient to edit texts with formulas.
As an option: Put a PDF file online and post just a reference to it in a blog.
Better options?
Best Answer
If it is interesting for general audience, Amer. Math. Monthly would be a choice; If it is also elementary, you may consider Elemente der Mathematik; If you are patient enough, you may try Mathematical Notes (Russia).