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 A039000 #20 Jun 20 2021 14:51:12 %S A039000 2,3,8,11,15,19,21,26,28,30,35,36,47,51,59,61,65,69,73,75,80,86,88,92, %T A039000 96,100,102,107,110,114,126,136,138,143,144,155,159,166,172,174,179, %U A039000 185,187,190,192,197,198,209,213,221,223,227,231,235,237,242,247,253 %N A039000 Numbers whose base-3 representation has the same number of 0's and 1's. %H A039000 Daniel Starodubtsev, <a href="/A039000/b039000.txt">Table of n, a(n) for n = 1..10000</a> %t A039000 Select[Range[300],DigitCount[#,3,0]==DigitCount[#,3,1]&] (* _Harvey P. Dale_, Sep 04 2020 *) %Y A039000 Cf. A007089, A077267, A062756. %K A039000 nonn,base,easy %O A039000 1,1 %A A039000 _Olivier Gérard_