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 A303573 #12 Dec 29 2018 15:49:01 %S A303573 101,111,101,10001,101101,1010101,1001001,101101,1010101,10011001, %T A303573 10011001,10111101,100111001,100101001,10111101,10111101,100111001, %U A303573 1000110001,1000110001,1001111001,1001111001,1001111001,1011111101,1011111101,10001110001,10001010001 %N A303573 a(n) = palindrome arising when A230891(n+1) is formed (if there is more than one, use the smallest). %C A303573 Let A230891(n) = X, A230891(n+1) = Y. The binary digits of X and Y can be rearranged to form a base-2 palindrome, possibly in several ways; a(n) is the smallest such palindrome. %H A303573 Rémy Sigrist, <a href="/A303573/b303573.txt">Table of n, a(n) for n = 0..29999</a> %H A303573 Rémy Sigrist, <a href="/A303573/a303573.gp.txt">PARI program for A303573</a> %o A303573 (PARI) See Links section. %Y A303573 Cf. A230891. %K A303573 nonn,base %O A303573 0,1 %A A303573 _N. J. A. Sloane_, Apr 27 2018 %E A303573 More terms from _Rémy Sigrist_, Dec 27 2018