DigiNews

Summary

The Kolakoski sequence is a self-generating sequence over the alphabet {1,2} where the values describe the lengths of runs of 1s and 2s in the sequence. It is equal to its own run-length encoding, making it a classic example of a nontrivial self-describing sequence; many properties (like the density of 1s versus 2s) remain open questions. The article outlines its definition, historical notes, and related variations.