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 A043477 #10 Apr 24 2021 20:42:18 %S A043477 6,15,24,33,42,51,54,55,56,57,58,59,61,62,69,78,87,96,105,114,123,132, %T A043477 135,136,137,138,139,140,142,143,150,159,168,177,186,195,204,213,216, %U A043477 217,218,219,220,221,223,224,231,240,249,258 %N A043477 Numbers having one 6 in base 9. %t A043477 Select[Range[300],DigitCount[#,9,6]==1&] (* _Harvey P. Dale_, Feb 06 2019 *) %Y A043477 Cf. A007095. %K A043477 nonn,base %O A043477 1,1 %A A043477 _Clark Kimberling_