Soft Question: Documentation of Important but Commonplace Calculations I've noticed the following about some facts in probability and statistics (it is probably true more generally).  Some results (formulas, for instance) may be moderately straightforward to derive and check, but they are not documented anywhere (at least anywhere easy to find).  So, everyone working on that problem needs to perform (and double-check) all those calculations for themselves when doing their work.

For example, the existence and formulae for the moments of some probability distribution may not be very easy to search for but may take about an hour or two derive and check.

I feel that the research in the community would proceed quicker if these calculations were documented somewhere.  What is the standard way of addressing this situation?  


Just do the calculation yourself, and don't worry about the rest of the community
Write a blog post
Write it up on Wikipedia
Write a so-called "note" on something like arXiv


I should note that I am pretty new to the game of research.
While my academic background is in theoretical CS rather than "pure" Math - it was mostly combinatorics and probability, so I feel qualified to tell you that:

AFAICT there isn't a standard. I suggest:


Leave calculations private? Definitely not!
Write a blog post - Most people don't have a blog. Also, a blog is not the most accessible medium for results in Math, as online resources go. It won't show up in places like, say, Google Scholar.  Also, some blogging platforms are not very stable over many years. Bottom line: If you do blog about things like this, possibly write a blog post in conjuction with something else.
Write it up on Wikipedia If the result itself is basic and commonly-used enough to merit a Wikipedia page, then sure. But - it might only merit a mention in some other page, in which case it doesn't make sense to try and stick a proof/calculation in there.
Write a so-called "note" on something like arXiv  ---> Do this &lt;----. Collect severall related mini-results / calculations, describe them nicely, introduce them with a bit of motivation perhaps, find a reasonable title and publish it on arXiv. 


One last option:


Sneak it into some book : This option is not available to grad students, but if you're a more experienced academic writing a book (perhaps something introductory, but not just in that case) - put this stuff in an appendix. A great example is Appendix A of Alon and Spencer's The Probabilistic Method, about large deviation bounds. The book uses those all over, but isn't about these strictly-probability-theory results, so they're not a proper chapter.