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A081427 Class 8- primes. 15
2879, 20147, 25903, 34537, 46049, 58733, 63317, 65267, 69029, 69073, 74759, 80537, 86291, 86341, 103549, 106487, 108413, 112877, 120877, 131687, 135859, 138053, 140939, 141023, 147647, 155413, 157427, 165527, 172681, 187163, 189949, 207079 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, A18.

LINKS

R. J. Mathar, Table of n, a(n) for n = 1..20000

MATHEMATICA

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[20000], ClassMinusNbr[ Prime[ # ]] == 8 &]]

CROSSREFS

Cf. A005113, A056637, A005109, A005110, A005111, A005112, A081424, A081425, A081426, A081428, A081429, A081430.

Sequence in context: A254355 A261859 A286526 * A101999 A066174 A175750

Adjacent sequences:  A081424 A081425 A081426 * A081428 A081429 A081430

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Mar 20 2003

STATUS

approved

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Last modified November 12 09:29 EST 2019. Contains 329054 sequences. (Running on oeis4.)