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A187680
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a(n) = (product of divisors of n) mod (sum of divisors of n).
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9
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0, 2, 3, 1, 5, 0, 7, 4, 1, 10, 11, 20, 13, 4, 9, 1, 17, 21, 19, 20, 25, 16, 23, 36, 1, 4, 9, 0, 29, 0, 31, 8, 33, 22, 25, 83, 37, 4, 9, 40, 41, 48, 43, 8, 21, 28, 47, 88, 1, 8, 9, 76, 53, 96, 1, 16, 49, 34, 59, 120, 61, 4, 31, 1
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OFFSET
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1,2
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LINKS
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FORMULA
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MAPLE
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MATHEMATICA
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Table[Mod[Times@@Divisors[n], DivisorSigma[1, n]], {n, 70}] (* Harvey P. Dale, May 23 2021 *)
a[n_] := Mod[n^(DivisorSigma[0, n]/2), DivisorSigma[1, n]]; Array[a, 60] (* Amiram Eldar, Jun 18 2022 *)
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PROG
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(PARI) a(n) = my(d=divisors(n)); vecprod(d) % vecsum(d); \\ Michel Marcus, Jan 29 2019
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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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