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 A039292 #15 Jun 28 2021 04:34:58 %S A039292 19,23,44,48,69,73,79,84,89,95,96,97,103,108,113,115,116,117,144,148, %T A039292 169,173,194,198,204,209,214,220,221,222,228,233,238,240,241,242,269, %U A039292 273,294,298,319,323,329,334,339,345,346,347,353,358,363,365,366,367 %N A039292 Numbers whose base-5 representation has the same nonzero number of 3's and 4's. %t A039292 Select[Range[500],DigitCount[#,5,3]==DigitCount[#,5,4]>0&] (* _Harvey P. Dale_, Jan 06 2012 *) %Y A039292 Cf. A007091. %K A039292 nonn,base,easy %O A039292 1,1 %A A039292 _Olivier Gérard_