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A269349
Kolakoski-(1,7) sequence: a(n) is length of n-th run.
2
1, 7, 7, 7, 7, 7, 7, 7, 1, 1, 1, 1, 1, 1, 1, 7, 7, 7, 7, 7, 7, 7, 1, 1, 1, 1, 1, 1, 1, 7, 7, 7, 7, 7, 7, 7, 1, 1, 1, 1, 1, 1, 1, 7, 7, 7, 7, 7, 7, 7, 1, 7, 1, 7, 1, 7, 1, 7, 7, 7, 7, 7, 7, 7, 1, 1, 1, 1, 1, 1, 1, 7, 7, 7, 7, 7, 7, 7, 1, 1, 1, 1, 1, 1, 1, 7, 7
OFFSET
1,2
COMMENTS
17, 1777, 1777777711111117777777 are primes.
LINKS
Michael Baake and Bernd Sing, Kolakoski-(3,1) is a (deformed) model set, arXiv:math/0206098 [math.MG], 2002-2003.
MATHEMATICA
seed = {1, 7}; w = {}; i = 1; Do[w = Join[w, Array[seed[[Mod[i - 1, Length[seed]] + 1]]&, If[i > Length[w], seed, w][[i]]]]; i++, {n, 42}]; w
CROSSREFS
Cf. similar sequences listed in A269268.
Sequence in context: A232127 A195413 A083947 * A112114 A031182 A106705
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 26 2016
STATUS
approved