To some extent the Scheme and Haskell communities do this already, because their favored languages are compact enough to allow them to include their programs in more or less conventional math papers.
http://canonical.org/~kragen/sw/dev3/paperalgo is a notation I developed for writing procedural programs with paper and pencil, extending mathematical notation with lightweight notation for classes, methods/functions, assignment, iteration, conditionals, and pattern matching. For many years I have used it whenever I'm writing code on paper or a whiteboard, but still find it harder to read than more traditional notations like Python and Scheme.
In addition to compact code and explanation, it's often useful to have example inputs and outputs (the way spreadsheets and Jupyter notebooks or R notebooks do), as well as proofs.
I think it would be tougher to find anyone willing to read programs written like this. Requiring an explanation to understand the variables is very similar to encoding the variables names and putting a lookup table below. Why force someones eyes to dart back and forth between the program and lookup table, just to get an idea of what the variable are, rather than also including a very rough explanation of what they variables are doing, in the program itself, by giving them meaningful names?
We only have so much working memory. Giving variables names frees up a significant amount.
This was a good lesson for me, I won't do that again and I'm far more verbose now.
My thinking is that maybe math should learn from things like that as well, perhaps expanding equations and being more verbose within the equation instead of an explanation next to it would make maths more accessible to a broader audience.
You shouldn’t really read the equations before understanding what they are about.
They are usually written down to get rid of ambiguities of the natural language.
This, by the way, is probably the main reason math uses single letters for names (with some rules of thumb that hint at the type, like n for an integer, X for a scheme, calligraphic F for a sheaf, etc.).
Same reason one often sees I1 + I2+I3+I4 in estimates. For the moment you actively don't want the mental overload of all the details. You just want to know that there are four terms to be discussed, now forget about all others and let us start looking at the first one.
Similarly long notation/names just do not work well on blackboards/whiteboards.