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A001598
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Number of terms in {b(1)..b(n)} relatively prime to b(n), where b(n) = A001597(n).
(Formerly M2244 N0891)
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1
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1, 1, 1, 3, 2, 5, 5, 4, 2, 9, 5, 8, 5, 13, 12, 8, 5, 17, 8, 6, 11, 14, 11, 23, 7, 23, 26, 11, 16, 14, 15, 31, 10, 28, 16, 24, 15, 37, 9, 39, 16, 20, 27, 20, 31, 14, 43, 47, 23, 32, 20, 51, 17, 14, 54, 24, 30, 28, 27, 40, 57, 61, 20, 56, 26, 42, 30, 28, 68, 22
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OFFSET
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1,4
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REFERENCES
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N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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MATHEMATICA
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nn = 10^4; t = Join[{1}, Union[Flatten[Table[n^i, {i, Prime[Range[PrimePi[Log[2, nn]]]]}, {n, 2, nn^(1/i)}]]]]; Table[Count[GCD[Take[t, n], t[[n]]], 1], {n, Length[t]}] (* T. D. Noe, Aug 09 2012 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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