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 A043516 #14 Sep 17 2023 16:17:04 %S A043516 6666,16666,26666,36666,46666,56666,60666,61666,62666,63666,64666, %T A043516 65666,66066,66166,66266,66366,66466,66566,66606,66616,66626,66636, %U A043516 66646,66656,66660,66661,66662,66663,66664,66665,66667 %N A043516 Numbers having four 6's in base 10. %H A043516 Daniel Starodubtsev, <a href="/A043516/b043516.txt">Table of n, a(n) for n = 1..10000</a> %t A043516 Select[Range[70000],DigitCount[#,10,6]==4&] (* _Harvey P. Dale_, Sep 17 2023 *) %Y A043516 Subsequence of A011536. %K A043516 nonn,base %O A043516 1,1 %A A043516 _Clark Kimberling_