Apu attends a math lecture at MIT which features an amazing calculation. Apu does not get it and neither did 99.99% of the people watching the episode. In this video the Mathologer tells you everything nobody ever wanted to know about this mystery blackboard.
Thank you very much to Danil Dmitriev the official Mathologer translator for Russian for his subtitles.
Burkard Polster and Giuseppe Geracitano