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A084071
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Class 12+ primes.
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8
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68198461, 115084901, 138358573, 156811273, 213397621, 220576331, 234432217, 260050573, 282261961, 290996753, 330864497, 353653063, 371500819, 383616341, 406915273, 426240379, 445800983, 446707201, 449558323, 460339577, 472782553
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listen;
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internal format)
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OFFSET
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1,1
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REFERENCES
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R. K. Guy, Unsolved Problems in Number Theory, A18.
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LINKS
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MAPLE
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For Maple program see Mathar link in A005105.
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MATHEMATICA
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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[25000000], ClassPlusNbr[ Prime[ # ]] == 12 &]]
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CROSSREFS
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Cf. A005113, A005105, A005106, A005107, A005108, A081633, A081634, A081635, A081636, A081637, A081638, A081639.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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