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 A023692 #10 Sep 13 2023 07:28:35 %S A023692 1,3,5,7,9,11,15,17,19,21,23,25,27,29,33,35,45,47,51,53,55,57,59,61, %T A023692 63,65,69,71,73,75,77,79,81,83,87,89,99,101,105,107,135,137,141,143, %U A023692 153,155,159,161,163,165,167,169,171,173,177,179 %N A023692 Numbers with a single 1 in their ternary expansion. %H A023692 Seiichi Manyama, <a href="/A023692/b023692.txt">Table of n, a(n) for n = 1..10000</a> %t A023692 Select[ Range[ 189 ], (Count[ IntegerDigits[ #, 3 ], 1 ]==1)& ] %K A023692 nonn,base,easy %O A023692 1,2 %A A023692 _Olivier Gérard_