I dunno if you could classify it as a short film but there is a film that I adore called Pi π.
It's in black and white and has the feel of a student film (Think
Clerks) and I think it's one of the better movies I've ever seen.
I don't wanna give away much but the story has the feeling of a thriller as a young man obsessed with finding secret patterns in nature and linking them back to π begins to discover very mysterious and frightening things as he digs deeper into the mystery surrounding the mathematical constant and finds he isn't the only one obsessed with π.
If you like thrillers, mystery movies or if you're just a fan of numbers and the strange coincidences around numbers chains then you owe it to yourself to see it. You can find it on youtube.
Trailerhttps://www.youtube.com/watch?v=jo18VIoR2xU