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 A098942 #7 Apr 18 2020 00:46:36
%S A098942 4,14,34,41,43,44,45,47,49,54,74,94,114,134,141,143,144,145,147,149,
%T A098942 154,174,194,314,334,341,343,344,345,347,349,354,374,394,411,413,414,
%U A098942 415,417,419,431,433,434,435,437,439,441,443,444,445,447,449,451,453,454
%N A098942 Numbers where 4 is the only even decimal digit.
%C A098942 This is a 10-automatic language. - _Charles R Greathouse IV_, Oct 05 2011
%H A098942 <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>
%o A098942 (Perl) for (0..1000) {
%o A098942 print "$_, " if (/^[134579]*4[134579]*$/)
%o A098942 } # _Charles R Greathouse IV_, Oct 05 2011
%K A098942 base,easy,nonn
%O A098942 1,1
%A A098942 _Eric Angelini_, Oct 21 2004