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 A118561 #20 Nov 18 2019 03:21:00
%S A118561 1,3,7,9,13,15,31,33,37,51,73,99,111,115,133,141,151,163,169,171,189,
%T A118561 193,195,303,327,331,339,361,385,391,393,399,511,529,535,537,579,583,
%U A118561 591,717,723,727,729,735,739,777,787,925,927,933,937,961,975,979,981,993
%N A118561 Lucky numbers for which the reversal is also a lucky number.
%H A118561 Amiram Eldar, <a href="/A118561/b118561.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..9014 from T. D. Noe)
%H A118561 W. Schneider, <a href="http://web.archive.org/web/2004/www.wschnei.de/number-theory/lucky-numbers-list.html">The First 1,000 Lucky Number</a>.
%e A118561 133 is in the sequence because (1) it is a lucky number and (2) the reversal 331 is also a lucky number.
%t A118561 nn = 10^3; t = Range[1, nn, 2]; sieve[n_] := Module[{k = t[[n]]}, t = Delete[t, Table[{i}, {i, k, Length[t], k}]]]; n = 1; While[t[[n]] < Length[t], n++; sieve[n]]; tr = Table[FromDigits[Reverse[IntegerDigits[i]]], {i, t}]; Intersection[t, tr] (* _T. D. Noe_, Mar 16 2013 *)
%Y A118561 Cf. A000959, A309406.
%K A118561 base,nonn
%O A118561 1,2
%A A118561 Luc Stevens (lms022(AT)yahoo.com), May 07 2006
%E A118561 Corrected and extended by Adam Panagos (adam.panagos(AT)gmail.com), May 10 2006
%E A118561 957 removed by _T. D. Noe_, Mar 16 2013