%I A081430
%S A081430 1266767,1520159,2486717,3316619,4144541,4512947,4836779,5389519,
%T A081430 5638379,6218827,6448979,6633457,6771419,6907247,7460149,7462639,
%U A081430 7600597,7739033,7874627,8153567,8291573,9110639,9112319,9121003
%N A081430 Class 11- primes.
%D A081430 R. K. Guy, Unsolved Problems in Number Theory, A18.
%H A081430 M. F. Hasler, <a href="b081430.txt">Table of n, a(n) for n=1..1000</a>
%t A081430 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]]; ClassMinusNbr[n_] := Length[NestWhileList[f, n, UnsameQ, All]] 
               - 3; Prime[ Select[ Range[300000, 1000000], ClassMinusNbr[ Prime[ 
               # ]] == 1 &]]
%Y A081430 Cf. A005113, A056637, A005109, A005110, A005111, A005112, A081424, A081425, 
               A081426, A081427, A081429.
%Y A081430 Sequence in context: A126174 A072892 A090615 this_sequence A147670 A058894 
               A118419
%Y A081430 Adjacent sequences: A081427 A081428 A081429 this_sequence A081431 A081432 
               A081433
%K A081430 nonn
%O A081430 1,1
%A A081430 Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 20 2003