A suggestion for your MathFiction collection. Many of the short stories of German writer Helga Königsdorf would qualify. She was both a mathematician and a writer, quite a bit of her work is set in the "Institut för Zahlographie" - "Institute for Numbergraphy".

It is tempting to read too much into the work of Helga Königsdorf, mathematician and writer, who survived the Nazis, the GDR, broken ideals and Parkinsons disease (and recently died in 2014 at age 75). She was one of the many who believed socialism to be a good thing and only the real existing one being faulty. Liability of the scientist and feminism were a main theme in her work, but given that her husband and son are mathematicians too, there is surprisingly little math in her stories.

"Meine ungehörigen Träume" (1978) - Contains the short stories "Lemma 1" and "Krise" which could be termed Social Math (in analogy to Social Fiction, a category of SF). Content: If I'd botched a lemma, so there, I'm an amateur. If a capitalist mathematician botches a lemma, it might *very* theoretically endanger his job. If a communist mathematician botches a lemma and ruins the 5 Year Plan...The botchess is rather lucky that her superiors, who signed the botchery without looking, have to take most of the flak.