%I #10 Jan 13 2014 12:14:30
%S 545587687,852480757,1048438561,1150849009,1323457987,1745980517,
%T 1756123441,1785398401,1798736161,1892507347,1937020021,2002155601,
%U 2136716521,2150905573,2229004913,2548101601,2671514917,2838761021
%N Class 13+ primes.
%D R. K. Guy, Unsolved Problems in Number Theory, A18.
%H M. F. Hasler, <a href="/A090468/b090468.txt">Table of n, a(n) for n=1..850</a>
%p For Maple program see Mathar link in A005105.
%t 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[195000000], ClassPlusNbr[ Prime[ # ]] == 13 &]]
%Y Cf. A005113, A005105 - A005108, A081633 - A081639, A084071, A129474.
%K nonn
%O 1,1
%A _Robert G. Wilson v_, Nov 26 2003
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