cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A249948 Gaps between single 1's in the Kolakoski sequence A000002.

Original entry on oeis.org

6, 3, 10, 5, 9, 3, 6, 3, 9, 6, 3, 9, 3, 6, 6, 3, 10, 5, 3, 9, 10, 9, 6, 3, 6, 3, 9, 6, 3, 9, 5, 9, 3, 6, 6, 3, 9, 10, 3, 5, 10, 9, 3, 5, 9, 3, 6, 3, 9, 3, 6, 6, 3, 10, 5, 3, 6, 3, 6, 9, 3, 6, 3, 6, 3, 5, 10, 3, 9, 5, 3, 10, 9, 3, 5, 10, 3, 6, 6, 3, 10, 5, 9, 3, 10, 9, 3, 6, 6
Offset: 1

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Except the first term, equals first difference of A249942.
The only possible values are 3, 5, 6, 9 and 10: a(n) cannot take the value 2, because it would imply the word 21212 which does not appear in the OK sequence; a(n) = 3 with the word 212-212, a(n) = 5 with 212-11-212, a(n) = 6 with 212-211-212 or 212-112-212, a(n) = 9 with 212-211-211-212 or 212-112-112-212, a(n) = 10 with 212-2112112-212. And from this it is easily seen that a(n) and a(n+1) cannot be equal unless a(n) = a(n+1) = 6 with the word 21-21122-1-22112-12.

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