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Search: id:A081426
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| 1439, 8629, 10067, 14683, 17257, 19577, 20389, 22643, 23743, 27103, 28219, 29399, 31657, 32633, 33107, 33113, 33863, 34259, 34513, 35951, 36137, 36887, 37379, 40127, 40637, 40759, 42179, 42209, 42767, 44519, 44579, 45139, 49019, 49669
(list; graph; listen)
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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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R. J. Mathar, Table of n, a(n) for n = 1..20000
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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]]; ClassMinusNbr[n_] := Length[NestWhileList[f, n, UnsameQ, All]] - 3; Prime[ Select[ Range[5200], ClassMinusNbr[ Prime[ # ]] == 7 &]]
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CROSSREFS
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Cf. A005113, A056637, A005109, A005110, A005111, A005112, A081424, A081425, A081427, A081428, A081429, A081430.
Sequence in context: A127491 A143475 A101798 this_sequence A101998 A063846 A078095
Adjacent sequences: A081423 A081424 A081425 this_sequence A081427 A081428 A081429
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 20 2003
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