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 A240972 #24 Feb 16 2025 08:33:21 %S A240972 1,6,10,28,72,352,240,832,672,2432,17408,12800,47104,55296,41984, %T A240972 126976,950272,2162688,2424832,3211264,18350080,5111808,90177536, %U A240972 377487360,55574528,394264576,247463936,3422552064,578813952,14763950080 %N A240972 Lexicographically earliest sequence such that (i) the binary plot of the sequence is symmetric with respect to the line y=x and (ii) the derived sequence (A000265(a(n))) contains only distinct terms. %C A240972 The first constraint means that writing the binary representation of each number vertically yields a symmetrical plot about the line y = x (see the binary plot). %C A240972 The second constraint ensures that the sequence contains only distinct terms, and differs from A000079. %C A240972 The keywords "nice" and "look" are based on the fact that the binary plot is very interesting. - _N. J. A. Sloane_, Aug 22 2014 %H A240972 Paul Tek, <a href="/A240972/b240972.txt">Table of n, a(n) for n = 1..3313</a> %H A240972 Paul Tek, <a href="/A240972/a240972.png">Binary plot of the first hundred terms</a> %H A240972 Paul Tek, <a href="/A240972/a240972.pl.txt">Perl program for this sequence</a> %H A240972 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/BinaryPlot.html">Binary Plot</a> %o A240972 (Perl) See Link section. %Y A240972 Cf. A230598, A240992 (odd part). %K A240972 nonn,base,nice,look %O A240972 1,2 %A A240972 _Paul Tek_, Aug 05 2014