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 A043417 #14 Apr 23 2023 22:02:06 %S A043417 6,13,20,27,34,41,42,43,44,45,46,47,55,62,69,76,83,90,91,92,93,94,95, %T A043417 96,104,111,118,125,132,139,140,141,142,143,144,145,153,160,167,174, %U A043417 181,188,189,190,191,192,193,194,202,209,216,223 %N A043417 Numbers whose base-7 representation contains exactly one 6. %t A043417 Select[Range[300],DigitCount[#,7,6]==1&] (* _Harvey P. Dale_, Dec 26 2018 *) %Y A043417 Cf. A007093. %K A043417 nonn,base %O A043417 1,1 %A A043417 _Clark Kimberling_