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.
%I A269352 #5 Mar 07 2016 06:15:55
%S A269352 1,10,10,10,10,10,10,10,10,10,10,1,1,1,1,1,1,1,1,1,1,10,10,10,10,10,
%T A269352 10,10,10,10,10,1,1,1,1,1,1,1,1,1,1,10,10,10,10,10,10,10,10,10,10,1,1,
%U A269352 1,1,1,1,1,1,1,1,10,10,10,10,10,10,10,10,10,10,1,1,1
%N A269352 Kolakoski-(1,10) sequence: a(n) is length of n-th run.
%C A269352 No prime number with the union of many terms.
%H A269352 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 A269352 seed = {1, 10}; 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 A269352 Cf. similar sequences listed in A269268.
%K A269352 nonn,easy
%O A269352 1,2
%A A269352 _Vincenzo Librandi_, Mar 02 2016