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 A250033 #11 Dec 02 2014 16:49:19
%S A250033 1,2,2,24,15,45,35,280,630,2100,2310,27720,10010,140140,150150,480480,
%T A250033 255255,2297295,4849845,96996900,101846745,106696590,111546435,
%U A250033 669278610,929553625,966735770,1003917915,3123300180,3234846615,48522699225,100280245065,1604483921040,6618496174290,6819056664420,7019617154550,7220177644680
%N A250033 a(n) gives the denominators for A250031(n) as well as for A250032(n).
%C A250033 See the comments in sequences A250031 and A250032.
%H A250033 Stanislav Sykora, <a href="/A250033/b250033.txt">Table of n, a(n) for n = 1..1000</a>
%H A250033 S. Sykora, On some number densities related to coprimes, Stan's Library, Vol.V, Nov 2014, DOI: <a href="http://dx.doi.org/10.3247/SL5Math14.005">10.3247/SL5Math14.005</a>
%F A250033 a(n)=A250031(n)+A250032(n).
%o A250033 (PARI) s_aux(n,p0,inp)={my(t=0/1,tt=0/1,in=inp,pp);while(1,pp=p0*prime(in);tt=n\pp;if(tt==0,break,t+=tt/pp-s_aux(n,pp,in++)));return(t)};
%o A250033 s(n)=1+s_aux(n,1,1);
%o A250033 a=vector(1000,n,denominator(s(n-1)/n))
%Y A250033 Cf. A250031, A250032.
%K A250033 nonn,frac
%O A250033 1,2
%A A250033 _Stanislav Sykora_, Nov 16 2014