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 A156264 #7 Dec 16 2017 05:31:38 %S A156264 1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2, %T A156264 1,1,1,1,1,1,1,1,2,1,1,2,2,2,2,1,2,2,1,1,2,2,2,2,1,1,2,1,1,1,1,1,1,1, %U A156264 1,1,1,1,1,1,1,1,1,2,2,1,1,1,1,2,1,1,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 %N A156264 a(n) = A000002(3*n-2), where A000002 is the Kolakoski sequence. %H A156264 Antti Karttunen, <a href="/A156264/b156264.txt">Table of n, a(n) for n = 1..12000</a> %o A156264 (PARI) %o A156264 up_to = 12000; %o A156264 v000002 = [1, 2, 2]; m=3; while(length(v000002) < 3*(1+up_to), v000002 = concat( v000002, vector(v000002[m], i, 2-m%2)); m++); \\ after PARI-code in A000002. %o A156264 A000002(n) = v000002[n]; %o A156264 A156264(n) = A000002((3*n)-2); \\ _Antti Karttunen_, Dec 15 2017 %Y A156264 Cf. A000002, A074264. %K A156264 nonn %O A156264 1,7 %A A156264 _Benoit Cloitre_, Feb 07 2009