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 A023722 #10 Sep 14 2023 08:06:58 %S A023722 0,5,10,15,20,26,27,28,29,30,35,40,45,51,52,53,54,55,60,65,70,76,77, %T A023722 78,79,80,85,90,95,101,102,103,104,105,110,115,120,131,132,133,134, %U A023722 136,137,138,139,141,142,143,144,146,147,148,149 %N A023722 Numbers with a single 0 in their base 5 expansion. %H A023722 Seiichi Manyama, <a href="/A023722/b023722.txt">Table of n, a(n) for n = 1..10000</a> %t A023722 Select[ Range[ 0, 150 ], (Count[ IntegerDigits[ #, 5 ], 0 ]==1)& ] %K A023722 nonn,base,easy %O A023722 1,2 %A A023722 _Olivier Gérard_