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 A161175 #15 Mar 14 2024 18:11:41 %S A161175 1,1,2,1,2,2,1,1,2,2,1,2,1,1,2,1,2,2,1,2,1,1,2,2,1,1,2,1,2,2,1,1,2,2, %T A161175 1,2,1,1,2,2,1,1,2,1,2,2,1,2,1,1,2,1,2,2,1,1,2,2,1,2,1,1,2 %N A161175 Triangle read by rows, modified Thue-Morse sequence (A010060 with offset 1): change 0 to 2, else 1. %C A161175 Row sums = A003945: (1, 3, 6, 12, 24,...). %C A161175 Rows tend to A001285: (1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 1, 2,...). %H A161175 Paolo Xausa, <a href="/A161175/b161175.txt">Table of n, a(n) for n = 1..8191</a> (rows 1..13 of the triangle, flattened). %F A161175 Given A010060 starting with offset 1, change zeros to 2, retain 1's. %F A161175 By rows, (n+1)-th row = n-th row with n-th row appended under morphism 1->2, 2->1. %e A161175 First few rows of the triangle = %e A161175 1; %e A161175 1, 2; %e A161175 1, 2, 2, 1; %e A161175 1, 2, 2, 1, 2, 1, 1, 2; %e A161175 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1; %e A161175 ... %e A161175 Given A010060 starting with 1 (below, top row); 0->2, else 1: %e A161175 A010060: (1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1,...) %e A161175 A161175: (1, 1, 2, 1, 2, 2, 1, 1, 2, 2, 1,...) %e A161175 Triangle read by rows, row 4 = (1, 2, 2, 1, 2, 1, 1, 2) = (2, 1, 1, 2) appended to the right of (1, 2, 2, 1). %t A161175 ReplaceAll[ThueMorse[Range[127]],0->2] (* _Paolo Xausa_, Dec 18 2023 *) %Y A161175 Cf. A010060, A001285, A003945 %K A161175 nonn,tabf %O A161175 1,3 %A A161175 _Gary W. Adamson_, Jun 05 2009