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 A267622 #30 Feb 16 2025 08:33:29
%S A267622 1,101,10111,1011111,101111111,10111111111,1011111111111,
%T A267622 101111111111111,10111111111111111,1011111111111111111,
%U A267622 101111111111111111111,10111111111111111111111,1011111111111111111111111,101111111111111111111111111,10111111111111111111111111111
%N A267622 Binary representation of the n-th iteration of the "Rule 187" elementary cellular automaton starting with a single ON (black) cell.
%D A267622 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
%H A267622 Robert Price, <a href="/A267622/b267622.txt">Table of n, a(n) for n = 0..1000</a>
%H A267622 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ElementaryCellularAutomaton.html">Elementary Cellular Automaton</a>
%H A267622 S. Wolfram, <a href="http://wolframscience.com/">A New Kind of Science</a>
%H A267622 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%H A267622 <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>
%F A267622 Conjectures from _Colin Barker_, Jan 19 2016 and Apr 20 2019: (Start)
%F A267622 a(n) = 101*a(n-1)-100*a(n-2) for n>2.
%F A267622 G.f.: (1+10*x^2) / ((1-x)*(1-100*x)).
%F A267622 (End)
%t A267622 rule=187; rows=20; ca=CellularAutomaton[rule,{{1},0},rows-1,{All,All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]],{rows-k+1,rows+k-1}],{k,1,rows}]; (* Truncated list of each row *) Table[FromDigits[catri[[k]]],{k,1,rows}] (* Binary Representation of Rows *)
%Y A267622 Cf. A267621, A140529.
%K A267622 nonn,easy
%O A267622 0,2
%A A267622 _Robert Price_, Jan 18 2016