Many research papers include numerical results obtained through computation. Most of the time such computations are performed using software that is used by many mathematicians, i.e., Maple, Mathematica, or even C/C++ code. Should such code be included in the body of the published paper?

I've heard arguments from both sides:

- Including such code can greatly decrease the time taken by a referee to replicate the results,
- The code can be easily modified by further authors who wish to extend the result,
- The reader does not need to spend time searching the journal website or the Internet for any "auxilliary files" containing the code.

On the other hand,

- Pages of code degrade the aesthetic nature of the publication,
- The author might need to spend additional space explaining the coding decisions that were made in the algorithms,
- It is likely that there exist (much) better ways to write the same algorithms in the given, or any other, language.

So what is the standard in mathematical research papers that present numerical results, either as a main or as a side result? Should code be included within the body of the publication, as an auxilliary file, or not at all?