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 A319954 #19 Oct 04 2018 20:04:57
%S A319954 2,2,0,2,1,2,0,0,2,0,1,2,1,0,2,1,1,2,0,0,0,2,0,0,1,2,0,1,0,2,0,1,1,2,
%T A319954 1,0,0,2,1,0,1,2,1,1,0,2,1,1,1,2,0,0,0,0,2,0,0,0,1,2,0,0,1,0,2,0,0,1,
%U A319954 1,2,0,1,0,0,2,0,1,0,1,2,0,1,1,0,2,0,1
%N A319954 Infinite word over {0,1,2} formed from list of binary words of lengths 0, 1, 2, etc., including empty word, each prefixed by a 2.
%H A319954 Rémy Sigrist, <a href="/A319954/b319954.txt">Table of n, a(n) for n = 0..25000</a>
%H A319954 Carl Pomerance, John Michael Robson, and Jeffrey Shallit, <a href="https://doi.org/10.1016/S0304-3975(96)00189-2">Automaticity II: Descriptional complexity in the unary case</a>, Theoretical computer science 180.1-2 (1997): 181-201.
%F A319954 a(n) = A030302(n+1) + [n belongs to A001855] (where [] is an Iverson bracket). - _Rémy Sigrist_, Oct 04 2018
%e A319954 The word written without commas:
%e A319954 220212002012102112000200120102011210021012110211120000200012001020011...
%o A319954 (PARI) k=0; for (n=0, oo, b=binary(n+1); b[1]++; for (i=1, #b, print1 (b[i] ", "); if (k++==87, quit))) \\ _Rémy Sigrist_, Oct 04 2018
%Y A319954 Cf. A001855, A030302, A214339, A319953.
%K A319954 nonn,base
%O A319954 0,1
%A A319954 _N. J. A. Sloane_, Oct 04 2018
%E A319954 Data corrected and extended by _Rémy Sigrist_, Oct 04 2018