I would like to add the MathOverflow icon to Academicons together with some other mathematical research related icons. Does anyone know where I could get/request a vector version of the MathOverflow icon (and possibly logo) to include in the collection?
Just some suggestion on where the logo could be obtained. (In addition to the comment by j.c. which offers some way to get it.
If you look at some posts tagged design you can see that this user was involved in creation the design for MathOverflow site during the transition to the Stack Exchange network. (You can see that all answers by this user are related to the site design and it is clear from them that this user at least helped with some stuff - I would even guess that they had the main responsibility for taking care of how the site looks, but I did not see this explicitly stated in those posts.) However after looking at their network profile, it seem that they weren't really active for some time. (They were online quite recently, as Asaf Karagila pointed out in a comment, but the last time this user made a post or a comment was August 2016.)
However, the MathOverflow site was originally a standalone site using Stack Exchange software. So the logo predates this transition. So people who started the site are in the best position to help you. And the moderators of MathOverflow are probably in good position to get to them. (In fact, Scott Morrison was definitely involved in creation of the site,1 I am not sure whether some of other moderators were part of that too - but he is the only one of the current moderator team which has been moderator already from the start.)
I kind of expected that one of the mods responds to your question here. (Since the moderators get notifications about new meta posts in their inbox, it's rather unlikely that none of them is aware of this post.) Still, as explained in another post, you can contact MO moderators at
1Scott Morrison was one of the authors of the article about creation of MO in Notices and also of the announcement of this site at Secret Blogging Seminar.
This might be closer to a longer comment than a real answer - I will gladly convert this to comment (or series of comments) - if the prevalent opinion is that this is the preferable course of action. (Although I assume that a bit of shortening will be needed to do that.)
Conclusion: according to Scott Morrison, the only file that still exists is the SVG file from the comment by @j.c.. Copyright issues were addressed in Scott Morrison's answer to another question. I'll be able to reproduce the vector icon from the logo and the raster icon.