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 A071573 #7 Mar 28 2015 14:47:19
%S A071573 1,14,114,594,2532,9658,34066,113930,366358,1141614,3465398,10291022,
%T A071573 29988178,85961454,242870564,677436550,1867877934
%N A071573 a(1) = 1; a(n) = a(n-1)-th nontotient number.
%F A071573 a(3)=114 is the 14th = a(2)-th term in A005277.
%t A071573 a = Table[0, {10^6}]; Do[b = EulerPhi[n]/2; If[b < 10^6 + 1, a[[b]] = 1], {n, 1, 2 10^7}]; b = Select[ Range[10^6], a[[ # ]] == 0 &]; c = 1; Do[ Print[c]; c = 2b[[c]], {n, 0, 7}]
%Y A071573 Cf. A005277, A072415.
%K A071573 more,nonn
%O A071573 1,2
%A A071573 _Robert G. Wilson v_, Jun 20 2002
%E A071573 Changed offset to match formula and a(11)-a(17) from _Donovan Johnson_, Feb 12 2011