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 A043322 #19 Dec 09 2021 19:26:03 %S A043322 9,18,28,29,30,33,36,45,55,56,57,60,63,72,85,86,88,89,91,92,93,96,100, %T A043322 101,102,105,109,110,111,114,117,126,136,137,138,141,144,153,166,167, %U A043322 169,170,172,173,174,177,181,182,183,186,190,191 %N A043322 Numbers having two 0's in base 3. %t A043322 Select[Range[200],DigitCount[#,3,0]==2&] (* _Harvey P. Dale_, Dec 09 2021 *) %Y A043322 Cf. A007089. %K A043322 nonn,base %O A043322 1,1 %A A043322 _Clark Kimberling_