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A263837
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Non-abundant numbers (or nonabundant numbers): complement of A005101; numbers k for which sigma(k) <= 2*k.
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17
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1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, 22, 23, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 37, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 57, 58, 59, 61, 62, 63, 64, 65, 67, 68, 69, 71, 73, 74, 75, 76, 77, 79, 81, 82, 83, 85, 86, 87, 89, 91, 92, 93, 94, 95, 97, 98, 99
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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MATHEMATICA
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Select[Range[100], DivisorSigma[1, #] <= 2*# &] (* Amiram Eldar, Mar 14 2024 *)
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PROG
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(Haskell)
a263837 n = a263837_list !! (n-1)
a263837_list = filter (\x -> a001065 x <= x) [1..]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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Additional description to the definition added by Antti Karttunen, Aug 28 2020
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STATUS
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approved
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