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A247180
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Numbers with nonrepeating smallest prime factor.
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9
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2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 18, 19, 21, 22, 23, 26, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 46, 47, 50, 51, 53, 54, 55, 57, 58, 59, 61, 62, 65, 66, 67, 69, 70, 71, 73, 74, 75, 77, 78, 79, 82, 83, 85, 86, 87, 89, 90, 91, 93, 94, 95, 97, 98
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OFFSET
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1,1
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COMMENTS
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Complement of the union of {1} and A283050. The asymptotic density of this sequence is 1 - A283071 = 0.6699019646... - Amiram Eldar, Dec 08 2020
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LINKS
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FORMULA
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MATHEMATICA
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Select[Range[100], FactorInteger[#][[1, 2]]==1&] (* Harvey P. Dale, Jan 29 2020 *)
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PROG
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(Haskell)
a247180 n = a247180_list !! (n-1)
a247180_list = filter ((== 1) . a067029) [1..]
(PARI) isok(m) = (m>1) && (factor(m)[1, 2] == 1); \\ Michel Marcus, Dec 08 2020
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CROSSREFS
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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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