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A340110
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Coreful 4-abundant numbers: numbers k such that csigma(k) > 4*k, where csigma(k) is the sum of the coreful divisors of k (A057723).
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1
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10584000, 12700800, 15876000, 19051200, 21168000, 22226400, 25401600, 29635200, 31752000, 37044000, 38102400, 42336000, 44452800, 47628000, 50803200, 52920000, 55566000, 57153600, 59270400, 63504000, 64033200, 66679200, 74088000, 76204800, 79380000, 84672000
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OFFSET
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1,1
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COMMENTS
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A coreful divisor d of a number k is a divisor with the same set of distinct prime factors as k, or rad(d) = rad(k), where rad(k) is the largest squarefree divisor of k (A007947).
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LINKS
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EXAMPLE
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10584000 is a term since csigma(10584000) = 42653520 > 4 * 10584000.
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MATHEMATICA
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f[p_, e_] := (p^(e + 1) - 1)/(p - 1) - 1; s[1] = 1; s[n_] := Times @@ (f @@@ FactorInteger[n]); Select[Range[10^8], s[#] > 4*# &]
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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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