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 A098947 #11 Apr 18 2020 00:49:08
%S A098947 5,25,45,50,52,54,55,56,58,65,85,205,225,245,250,252,254,255,256,258,
%T A098947 265,285,405,425,445,450,452,454,455,456,458,465,485,500,502,504,505,
%U A098947 506,508,520,522,524,525,526,528,540,542,544,545,546,548,550,552,554
%N A098947 Numbers where 5 is the only odd decimal digit.
%C A098947 This is a 10-automatic language. - _Charles R Greathouse IV_, Oct 03 2011
%H A098947 <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>
%t A098947 Select[Range[600],Union[Select[IntegerDigits[#],OddQ]]=={5}&] (* _Harvey P. Dale_, Jun 13 2014 *)
%o A098947 (Perl) for (0..1000) {
%o A098947 print "$_, " if (/^[024568]*5[024568]*$/)
%o A098947 } # _Charles R Greathouse IV_, Oct 05 2011
%K A098947 base,easy,nonn
%O A098947 1,1
%A A098947 _Eric Angelini_, Oct 21 2004