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 A039567 #23 Jul 01 2021 03:39:21
%S A039567 1,3,6,8,16,18,31,33,41,43,54,70,81,83,91,93,102,110,139,147,156,158,
%T A039567 166,168,179,195,206,208,216,218,227,235,259,269,271,273,279,295,329,
%U A039567 345,351,353,355,365,389,397,406,408,416,418,429,445,456,458,466,468
%N A039567 Numbers whose base-5 representation has the same number of 0's, 2's and 4's.
%H A039567 Robert Israel, <a href="/A039567/b039567.txt">Table of n, a(n) for n = 1..10000</a>
%e A039567 54 is a term since 54 in base 10 is 204 in base 5.
%p A039567 filter:= proc(n) local L,q;
%p A039567 L:= convert(n,base,5);
%p A039567 nops(map(numboccur,{0,2,4},L))=1
%p A039567 end proc:
%p A039567 select(filter,[$1..1000]); # _Robert Israel_, Apr 09 2018
%t A039567 ok5Q[n_]:=Module[{dc5=DigitCount[n,5]},dc5[[2]]==dc5[[4]]==dc5[[5]]]; Select[Range[500],ok5Q] (* _Harvey P. Dale_, Mar 05 2011 *)
%Y A039567 Cf. A007091, A039562, A039563, A039564, A039565, A039566.
%K A039567 nonn,base,easy
%O A039567 1,2
%A A039567 _Olivier Gérard_