Fans, particularly the maths whizzes among them, often spot plenty of Easter eggs and hidden references in shows that are all to do with numbers.  This is due to the fact that many of people involved in the production of The Simpsons are huge maths buffs, the Mirror reports. The first-ever episode of the series in 1989 had plenty of mathematics references with jokes about calculus. And if your worst nightmare is maths, then it seems fitting that the Halloween special “Treehouse of Horror VI” featured a pretty intense five minutes of maths.

In one scene, the letters P and NP can be seen over Homer’s right shoulder, which might not mean anything to most viewers, but it’s actually an unsolved theoretical computer science problem. The puzzle has a reward of $1million for whoever solves the mystery.  

As reported by The Guardian, many of The Simpsons writers have a pretty impressive mathematical background. Al Jean, who is now the executive producer, worked on the first series and studied mathematics at Harvard University at the age of just 16.  Jeff Westbrook was a writer and a producer for The Simpsons, and he’s a former academic and algorithms researcher at Yale University