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 A334820 #54 Aug 22 2021 13:27:42 %S A334820 0,1,0,1,1,0,1,0,1,1,0,1,1,1,0,1,0,1,1,0,1,1,0,1,0,1,1,0,1,1,1,0,1,0, %T A334820 1,1,0,1,0,1,0,1,1,0,1,1,1,0,1,0,1,1,0,1,1,0,1,0,1,1,0,1,1,1,0,1,0,1, %U A334820 1,0,1,1,0,1,1,0,1,1,1,0,1,0,1,1,0,1,1,0,1,0,1,1,0,1,1,1,0,1,0,1,1,0,1,0,1 %N A334820 Sequence is limit_{t->oo} s_t, where s_k = s_{k-1},s_{k-1}[k-1..end] starting with s_0 = s_0[0..1] = 0,1. %C A334820 A nonperiodic sequence of 0 and 1. %H A334820 Kevin Ryde, <a href="http://user42.tuxfamily.org/seq-A334820/index.html">PARI/GP code and explanation</a>. %p A334820 s:= proc(n) option remember; `if`(n=0, [0, 1][], %p A334820 (l-> [l[], l[n..-1][]][])([s(n-1)])) %p A334820 end: %p A334820 s(10); # gives 1035 = A005126(10) terms; # _Alois P. Heinz_, May 12 2020 %t A334820 a[n_] := If[n<2, n, Module[{k = Floor@Log[2, n], m = n}, m-=k+1; While[k >= 0, If[BitGet[m, k]==0, m++; If[BitGet[m, k]==1, Return[1]]]; k--]]; 0]; %t A334820 a /@ Range[0, 104] (* _Jean-François Alcover_, Nov 16 2020, after _Kevin Ryde_ *) %o A334820 (PARI) a(n) = { if(n, my(k=logint(n,2)); n-=k+1; while(k>=0, if(!bittest(n,k), n++; if(bittest(n,k), return(1))); k--)); 0; } \\ _Kevin Ryde_, Jun 26 2020 %Y A334820 Cf. A005126 (s lengths), A057215. %K A334820 nonn %O A334820 0,1 %A A334820 _Richard Aime Blavy_, May 12 2020