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 A026606 #16 Jul 11 2019 02:08:23 %S A026606 1,2,1,2,2,1,1,2,2,1,1,2,2,1,1,2,1,2,1,2,2,1,1,2,2,1,1,2,1,2,1,2,1,2, %T A026606 2,1,2,1,1,2,1,2,1,2,1,2,2,1,1,2,2,1,1,2,1,2,2,1,1,2,2,1,1,2,1,2,1,2, %U A026606 1,2,2,1,2,1,1,2,1,2,1,2,1,2,2,1,1,2,2,1,1,2 %N A026606 [1->null]-transform of three-symbol Thue-Morse A026600, with 1 subtracted. %C A026606 Old name was: a(n) = b(n)-1, where b(n) = n-th term of A026600 that is not a 1. %C A026606 From _Michel Dekking_, Apr 18 2019: (Start) %C A026606 This sequence is a morphic sequence, i.e., a letter-to-letter projection of a fixed point of a morphism. Let the morphism sigma be given by %C A026606 1->123, 2->456, 3->345,4->612, 5->561, 6->234, %C A026606 and let the letter-to-letter map delta be given by %C A026606 1->1, 2->2, 3->1, 4->2, 5->2, 6->1. %C A026606 Then (a(n)) = delta(x), where x = 1234... is a fixed point of sigma. %C A026606 This representation can be obtained by noting that this sequence, with 1 added, can also be viewed as the [1->23, 2->23, 3->32]-transform of A026600, and by doubling 1,2 and 3, renaming the resulting six letters as 1,2,3,4,5,6. %C A026606 (End) %Y A026606 Cf. A026605, A057215. %K A026606 nonn %O A026606 1,2 %A A026606 _Clark Kimberling_ %E A026606 Name changed by _Michel Dekking_, Apr 18 2019