login
Kolakoski-(1,8) sequence: a(n) is length of n-th run.
2

%I #16 Mar 04 2016 02:29:57

%S 1,8,8,8,8,8,8,8,8,1,1,1,1,1,1,1,1,8,8,8,8,8,8,8,8,1,1,1,1,1,1,1,1,8,

%T 8,8,8,8,8,8,8,1,1,1,1,1,1,1,1,8,8,8,8,8,8,8,8,1,1,1,1,1,1,1,1,8,1,8,

%U 1,8,1,8,1,8,8,8,8,8,8,8,8,1,1,1,1,1,1

%N Kolakoski-(1,8) sequence: a(n) is length of n-th run.

%C 188888888111111118888888811111111 is prime.

%H Vincenzo Librandi, <a href="/A269350/b269350.txt">Table of n, a(n) for n = 1..10000</a>

%H Michael Baake and Bernd Sing, <a href="http://arXiv.org/abs/math.MG/0206098">Kolakoski-(3,1) is a (deformed) model set</a>, arXiv:math/0206098 [math.MG], 2002-2003.

%t seed = {1, 8}; 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

%Y Cf. similar sequences listed in A269268.

%K nonn,easy

%O 1,2

%A _Vincenzo Librandi_, Feb 26 2016