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A217854
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Product of all divisors of n, positive or negative.
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11
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-1, 4, 9, -64, 25, 1296, 49, 4096, -729, 10000, 121, 2985984, 169, 38416, 50625, -1048576, 289, 34012224, 361, 64000000, 194481, 234256, 529, 110075314176, -15625, 456976, 531441, 481890304, 841, 656100000000, 961, 1073741824, 1185921
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OFFSET
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1,2
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COMMENTS
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a(n) is negative iff n is a square.
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LINKS
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FORMULA
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a(n) = (-n)^tau(n) = (-n)^A000005(n).
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MATHEMATICA
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a[n_] := (-n)^DivisorSigma[0, n]; Array[a, 33] (* Amiram Eldar, Aug 31 2023 *)
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PROG
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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