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 A081637 #7 Jan 13 2014 11:58:40
%S A081637 532801,710341,720617,1212487,1261157,1372081,1457293,1490429,1532173,
%T A081637 1657801,1788547,1789093,1809601,1829293,1887877,1944181,1960141,
%U A081637 1997587,2121853,2161853,2474413,2484049,2557441,2578801,2613607
%N A081637 Class 9+ primes.
%D A081637 R. K. Guy, Unsolved Problems in Number Theory, A18.
%H A081637 T. D. Noe, <a href="/A081637/b081637.txt">Table of n, a(n) for n=1..10000</a>
%p A081637 For Maple program see Mathar link in A005105.
%t A081637 PrimeFactors[n_Integer] := Flatten[ Table[ #[[1]], {1}] & /@ FactorInteger[n]]; f[n_Integer] := Block[{m = n}, If[m == 0, m = 1, While[ IntegerQ[m/2], m /= 2]; While[ IntegerQ[m/3], m /= 3]]; Apply[Times, PrimeFactors[m] + 1]]; ClassPlusNbr[n_] := Length[ NestWhileList[f, n, UnsameQ, All]] - 3; Prime[ Select[ Range[196000], ClassPlusNbr[ Prime[ # ]] == 9 &]]
%Y A081637 Cf. A005113, A005105, A005106, A005107, A005108, A081633, A081634, A081635, A081636, A081638, A081639.
%K A081637 nonn
%O A081637 1,1
%A A081637 _Robert G. Wilson v_, Mar 20 2003