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1, 3, 6, 6, 7, 8, 9, 10, 9, 12, 12, 15, 14, 12, 14, 13, 18, 19, 18, 15, 18, 15, 20, 14, 24, 21, 18, 21, 24, 18, 24, 21, 27, 33, 30, 28, 28, 32, 36, 30, 21, 26, 27, 24, 27, 38, 30, 36, 35, 45, 36, 42, 39, 26, 44, 28, 40, 51, 30, 36, 28, 48, 54, 42, 45, 38, 31, 39, 36, 48, 60, 54
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listen;
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OFFSET
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1,2
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COMMENTS
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Arithmetic means of divisors of nonprime arithmetic numbers (A023883). - Amiram Eldar, Jun 06 2020
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LINKS
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MATHEMATICA
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meanDiv[n_] := DivisorSigma[1, n]/DivisorSigma[0, n]; Select[meanDiv /@ Select[Range[200], !PrimeQ[#] &], IntegerQ] (* Amiram Eldar, Jun 06 2020 *)
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PROG
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(PARI) f(x) = sigma(x)/numdiv(x);
apply(x->f(x), select(x->((denominator(f(x))==1) && !isprime(x)), [1..1000])) \\ Michel Marcus, Jun 06 2020
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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