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 A005108 M5350 #22 Jan 13 2014 11:56:19
%S A005108 73,313,443,617,661,673,677,691,739,757,823,887,907,941,977,1093,1109,
%T A005108 1129,1201,1213,1303,1361,1447,1453,1543,1553,1621,1627,1657,1753,
%U A005108 1811,1867,1873,1993,1997,2017,2081,2083,2113,2269,2273,2281,2293,2333,2341
%N A005108 Class 4+ primes (for definition see A005105).
%D A005108 R. K. Guy, Unsolved Problems in Number Theory, A18.
%D A005108 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A005108 T. D. Noe, <a href="/A005108/b005108.txt">Table of n, a(n) for n=1..10000</a>
%p A005108 For Maple program see Mathar link in A005105.
%t A005108 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[350], ClassPlusNbr[ Prime[ # ]] == 4 &]]
%Y A005108 Cf. A005113, A005105, A005106, A005107.
%K A005108 nonn
%O A005108 1,1
%A A005108 _N. J. A. Sloane_, _Simon Plouffe_
%E A005108 Edited and extended by _Robert G. Wilson v_, Mar 20 2003