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 A074262 #12 Jun 18 2013 06:06:46
%S A074262 4,13,16,22,28,31,40,48,51,58,67,70,78,85,94,97,103,112,115,121,124,
%T A074262 130,133,140,148,157,160,167,175,178,184,190,193,201,208,217,220,226,
%U A074262 229,238,244,247,253,256,265,271,274,283,291,294,303,310,319,322,328
%N A074262 Positions of '11' in Kolakoski sequence A000002.
%H A074262 Nathaniel Johnston, <a href="/A074262/b074262.txt">Table of n, a(n) for n = 1..10000</a>
%e A074262 Kolakoski sequence begins 1,2,2,1,1,2,1,2,2,1,2,2,1,1,... so 4 and 13 are in this sequence.
%t A074262 a2 = {1, 2, 2}; Do[ a2 = Join[a2, {1 + Mod[n - 1, 2]}], {n, 3, 300}, {i, 1, a2[[n]]}]; Split[a2] /. {1, 1} -> {0, 1} // Flatten // Position[#, 0]& // Flatten (* _Jean-François Alcover_, Jun 18 2013 *)
%Y A074262 Cf. A074263.
%K A074262 nonn,easy
%O A074262 1,1
%A A074262 _Jon Perry_, Sep 20 2002
%E A074262 Extended and offset changed by _Nathaniel Johnston_, May 02 2011