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 A023701 #12 Sep 13 2023 07:19:38 %S A023701 26,53,62,71,74,77,78,79,107,134,143,152,155,158,159,160,170,179,182, %T A023701 185,186,187,197,206,209,212,213,214,218,221,222,223,227,230,231,232, %U A023701 234,235,237,238,269,296,305,314,317,320,321 %N A023701 Numbers with exactly 3 2's in their ternary expansion. %H A023701 Seiichi Manyama, <a href="/A023701/b023701.txt">Table of n, a(n) for n = 1..10000</a> %t A023701 Select[ Range[ 324 ], (Count[ IntegerDigits[ #, 3 ], 2 ]==3)& ] %K A023701 nonn,base,easy %O A023701 1,1 %A A023701 _Olivier Gérard_