Go Pro!

Problems > Brain Food > 2008

A Mysterious Sequence

Can you figure out the next number in this sequence?

1, 11, 21, 1211, 111221, ???

Congratulations to the following, who were high scorers for this past year:
AlphaSigChainsaw (96 points)
yoi55 (85 points)
lewanj (83 points)
beckyh (76 points)

View the solution
Word Equation: Comfort, Sun and Cards
A Girl and a Nail

Understanding Coronavirus Spread

A Question and Answer session with Professor Puzzler about the math behind infection spread.

Blogs on This Site

Reviews and book lists - books we love!
The site administrator fields questions from visitors.
Like us on Facebook to get updates about new resources
Pro Membership