A269348 Kolakoski-(1,6) sequence: a(n) is length of n-th run.

1, 6, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1, 6, 1, 6, 1, 6, 1, 6, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1, 6, 1, 6, 1, 6, 1, 6, 6

Offset: 1

Author

Vincenzo Librandi, Feb 25 2016

Keywords

• nonn
• easy

Comments

16666661111, 1666666111111, 1666666111111666666111111666666111111616161666666111111666666111 are primes.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..10000
• Michael Baake and Bernd Sing, Kolakoski-(3,1) is a (deformed) model set, arXiv:math/0206098 [math.MG], 2002-2003.

Crossrefs

Cf. similar sequences listed in A269268.

Programs

Mathematica

seed = {1, 6}; w = {}; i = 1; Do[w = Join[w, Array[seed[[Mod[i - 1, Length[seed]] + 1]] &, If[i > Length[w], seed, w][[i]]]]; i++, {n, 250}]; w (* from Ivan Neretin in similar sequences *)