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 A133083 #12 Mar 06 2022 08:34:52
%S A133083 1,2,1,2,1,1,2,1,2,1,2,1,2,1,1,2,1,2,1,2,1,2,1,2,1,2,1,1,2,1,2,1,2,1,
%T A133083 2,1,2,1,2,1,2,1,2,1,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,1,2,1,
%U A133083 2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,1
%N A133083 A000012 * A133080.
%C A133083 Row sums = A032766, congruent to {0,1} (mod 3): (1, 3, 4, 6, 7, 9, 10, ...).
%H A133083 G. C. Greubel, <a href="/A133083/b133083.txt">Table of n, a(n) for the first 50 rows, flattened</a>
%F A133083 A000012 * A133080 as infinite lower triangular matrices.
%e A133083 First few rows of the triangle:
%e A133083 1;
%e A133083 2, 1;
%e A133083 2, 1, 1;
%e A133083 2, 1, 2, 1;
%e A133083 2, 1, 2, 1, 1;
%e A133083 2, 1, 2, 1, 2, 1;
%e A133083 ...
%t A133083 T[n_, k_] := If[k == n, 1, 1 + (1 - (-1)^k)/2 ]; Table[T[n, k], {n, 1, 10}, {k, 1, n}] (* _G. C. Greubel_, Oct 21 2017 *)
%o A133083 (PARI) for(n=1,10, for(k=1,n, print1(if(k==n, 1, 1 + (1-(-1)^k)/2), ", "))) \\ _G. C. Greubel_, Oct 21 2017
%Y A133083 Cf. A133080, A000012, A032766.
%K A133083 nonn,tabl
%O A133083 1,2
%A A133083 _Gary W. Adamson_, Sep 08 2007