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 A005106 M4889 #21 Mar 26 2024 07:38:21
%S A005106 13,19,29,41,43,59,61,67,79,83,89,97,101,109,131,137,139,149,167,179,
%T A005106 197,199,211,223,229,239,241,251,263,269,271,281,283,293,307,317,349,
%U A005106 359,367,373,419,433,439,449,461,479,499,503,509,557,563,577,587,593
%N A005106 Class 2+ primes (for definition see A005105).
%D A005106 R. K. Guy, Unsolved Problems in Number Theory, A18.
%D A005106 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A005106 T. D. Noe, <a href="/A005106/b005106.txt">Table of n, a(n) for n=1..10000</a>
%F A005106 {prime(n): A126433(n) = 2}. - _R. J. Mathar_, Mar 26 2024
%p A005106 For Maple program see Mathar link in A005105.
%t A005106 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[120], ClassPlusNbr[ Prime[ # ]] == 2 &]]
%Y A005106 Cf. A005113, A005105, A005107, A005108.
%K A005106 nonn
%O A005106 1,1
%A A005106 _N. J. A. Sloane_, _Simon Plouffe_
%E A005106 Edited and extended by _Robert G. Wilson v_, Mar 20 2003