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 A098948 #16 Jul 27 2021 15:12:50
%S A098948 7,27,47,67,70,72,74,76,77,78,87,207,227,247,267,270,272,274,276,277,
%T A098948 278,287,407,427,447,467,470,472,474,476,477,478,487,607,627,647,667,
%U A098948 670,672,674,676,677,678,687,700,702,704,706,707,708,720,722,724,726
%N A098948 Numbers where 7 is the only odd decimal digit.
%C A098948 This is a 10-automatic language. - _Charles R Greathouse IV_, Oct 03 2011
%H A098948 <a href="/index/Ar#10-automatic">Index entries for 10-automatic sequences</a>
%p A098948 q:= n-> is(select(c-> c::odd, {convert(n, base, 10)[]})={7}):
%p A098948 select(q, [$1..887])[]; # _Alois P. Heinz_, Jul 27 2021
%t A098948 Select[Range[1000],Union[Select[IntegerDigits[#],OddQ]]=={7}&] (* _Harvey P. Dale_, May 24 2012 *)
%o A098948 (Perl) for (0..1000) {
%o A098948 print "$_, " if (/^[024678]*7[024678]*$/)
%o A098948 } # _Charles R Greathouse IV_, Oct 05 2011
%o A098948 (Python)
%o A098948 def ok(n): return set("13579") & set(str(n)) == {'7'}
%o A098948 print(list(filter(ok, range(727)))) # _Michael S. Branicky_, Jul 27 2021
%K A098948 base,easy,nonn
%O A098948 1,1
%A A098948 _Eric Angelini_, Oct 21 2004