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A081425 Class 6- primes. +0
14
719, 1319, 1699, 2447, 3343, 4079, 4139, 4457, 4517, 4679, 4703, 5273, 5647, 6653, 6793, 7523, 7529, 7559, 8599, 9227, 9587, 9623, 9839, 10159, 10343, 10723, 10771, 11069, 11213, 11279, 11321, 11489, 11863, 11887, 12163, 12917, 12919, 13163 (list; graph; listen)
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[1700], ClassMinusNbr[ Prime[ # ]] == 6 &]]

CROSSREFS

Cf. A005113, A056637, A005109, A005110, A005111, A005112, A081424, A081426, A081427, A081428, A081429, A081430.

Sequence in context: A151631 A034587 A111416 this_sequence A101797 A144767 A127227

Adjacent sequences: A081422 A081423 A081424 this_sequence A081426 A081427 A081428

KEYWORD

nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 20 2003

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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