Permanent problem IDPPL 096
Combinatorics on words
Settle any one of five questions about the Oldenburger–Kolakoski sequence: find a formula for its nth term; prove recurrence of every occurring finite word; prove reversal closure; prove closure under swapping 1 and 2; or prove that the limiting frequency of 1 exists and equals one half.
Settle any one of five questions about the Oldenburger–Kolakoski sequence: find a formula for its nth term; prove recurrence of every occurring finite word; prove reversal closure; prove closure under swapping 1 and 2; or prove that the limiting frequency of 1 exists and equals one half.
This is one shared 200 offer for resolving any one of the five questions, not five independently payable awards.
Be first to publish a solution in a refereed journal, or submit a short proof that Kimberling accepts as correct and complete. For solutions after 1 January 2025, Kimberling says the stated amount will be donated in the solver’s name to the Online Encyclopedia of Integer Sequences; it is not direct cash to the solver.
Current post-2025 form: a donation to OEIS in the solver’s name.