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A204825
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Abundant numbers with even sum of divisors.
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4
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12, 20, 24, 30, 40, 42, 48, 54, 56, 60, 66, 70, 78, 80, 84, 88, 90, 96, 102, 104, 108, 112, 114, 120, 126, 132, 138, 140, 150, 156, 160, 168, 174, 176, 180, 186, 192, 198, 204, 208, 210, 216, 220, 222, 224, 228, 234, 240, 246, 252, 258, 260, 264, 270, 272, 276, 280
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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Abundant number 12 is in sequence because sigma(12) = 28 (even number).
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MATHEMATICA
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aQ[n_] := EvenQ[(s = DivisorSigma[1, n])] && s > 2n; Select[Range[280], aQ] (* Amiram Eldar, Sep 02 2019 *)
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CROSSREFS
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Cf. A156903 (abundant numbers with odd sum of divisors), A204826 (deficient numbers with odd sum of divisors), A204827 (deficient numbers with even sum of divisors).
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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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