%I A005107 M5261
%S A005107 37,103,113,151,157,163,173,181,193,227,233,257,277,311,331,337,347,353,
%T A005107 379,389,397,401,409,421,457,463,467,487,491,521,523,541,547,569,571,
%U A005107 601,607,613,631,653,683,701,727,733,773,787,797,811,821,829,853,857
%N A005107 Class 3+ primes.
%D A005107 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005107 R. K. Guy, Unsolved Problems in Number Theory, A18.
%p A005107 For Maple program see Mathar link.
%t A005107 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[150], ClassPlusNbr[ Prime[ # ]] == 3 &]]
%Y A005107 Cf. A005113, A005105, A005106, A005108.
%Y A005107 Sequence in context: A142941 A105019 A090496 this_sequence A139934 A142051 
               A033215
%Y A005107 Adjacent sequences: A005104 A005105 A005106 this_sequence A005108 A005109 
               A005110
%K A005107 nonn
%O A005107 1,1
%A A005107 N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com)
%E A005107 Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 20 
               2003