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 A026613 #16 Apr 17 2019 03:18:09
%S A026613 1,0,2,0,2,0,2,1,1,0,2,0,2,1,1,1,0,1,2,1,1,1,0,2,0,2,1,0,2,0,2,1,1,1,
%T A026613 0,1,2,1,1,1,0,2,0,2,1,1,0,2,0,2,0,2,1,0,2,1,1,1,0,2,0,2,1,1,0,2,0,2,
%U A026613 0,2,1,1,0,2,0,2,1,1,1,0,2,0,2,0,2,1,1,1,0,1
%N A026613 Number of 2's between n-th 3 and (n+1)st 3 in A026600.
%C A026613 (a(n)) is a morphic sequence, i.e., a letter-to-letter projection of a fixed point of a morphism. See A026608 and A026610. - _Michel Dekking_, Apr 16 2019
%C A026613 The frequencies of 0's, 1's and 2's in (a(n)) are 4/13, 5/13 and 4/13. See A026610. - _Michel Dekking_, Apr 16 2019
%H A026613 Michael De Vlieger, <a href="/A026613/b026613.txt">Table of n, a(n) for n = 1..19682</a>
%t A026613 Rest@ Map[Count[#, 2] &, DeleteCases[SplitBy[#, # == 3 &], _?(# == {3} &)]] &@ Nest[Flatten[# /. {1 -> {1, 2, 3}, 2 -> {2, 3, 1}, 3 -> {3, 1, 2}}] &, {1}, 6] (* _Michael De Vlieger_, Apr 16 2019, after _Robert G. Wilson v_ at A026600 *)
%Y A026613 Cf. A026600, A026608, A026610.
%K A026613 nonn
%O A026613 1,3
%A A026613 _Clark Kimberling_