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 A284208 #17 Jun 24 2021 09:12:30 %S A284208 1,111,10001,1101011,101010101,11100000111,1000001000001, %T A284208 110110111011011,10100000000000101,1110111011101110111, %U A284208 100010100010001010001,11010110000000001101011,1010101000001000001010101,111000000000111000000000111,10000010100010001000101000001 %N A284208 Binary representation of generation n in the reversible cellular automaton RCA(3) when started with a single ON cell at generation 0. %H A284208 Robert Price, <a href="/A284208/b284208.txt">Table of n, a(n) for n = 0..999</a> %H A284208 Alan J. Macfarlane, <a href="https://doi.org/10.1088/0305-4470/37/45/006">Linear reversible second-order cellular automata and their first-order matrix equivalents</a>, Journal of Physics A: Mathematical and General 37.45 (2004): 10791. See Fig. 3. %H A284208 Robert Price, <a href="/A284208/a284208.bfile.txt">Diagram of the first 35 generations</a> %H A284208 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %H A284208 <a href="/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a> %e A284208 The second generation (starting at 0) of RCA(3) is x...x where "x" is an ON cell and "." is OFF. Treating this as a binary number yields 10001. Thus a(2) = 10001. %Y A284208 Cf. A059319, A284209. %K A284208 nonn %O A284208 0,2 %A A284208 _Robert Price_, Mar 22 2017