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A324980
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a(n) = Product_{d|n} (d*sigma(d)) where sigma(k) = the sum of the divisors of k (A000203).
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0
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1, 6, 12, 168, 30, 5184, 56, 20160, 1404, 32400, 132, 48771072, 182, 112896, 129600, 9999360, 306, 425782656, 380, 762048000, 451584, 627264, 552, 8427641241600, 23250, 1192464, 1516320, 4956585984, 870, 21767823360000, 992, 20158709760, 2509056, 3370896
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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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a(n) = (Product_{d|n} d) * (Product_{d|n} sigma(d)) = A007955(n) * A206032(n).
a(p) = p*(p+1) for p = primes (A000040).
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EXAMPLE
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a(6) = 1*sigma(1) * 2*sigma(2) * 3*sigma(3) * 6*sigma(6) = (1*1) * (2*3) * (3*4) * (6*12) = 5184.
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MATHEMATICA
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Array[Times @@ Map[# DivisorSigma[1, #] &, Divisors@ #] &, 34] (* Michael De Vlieger, Mar 24 2019 *)
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PROG
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(Magma) [&*[d * SumOfDivisors(d): d in Divisors(n)]: n in [1..100]]
(PARI) a(n) = my(p=1); fordiv(n, d, p *= d*sigma(d)); p; \\ Michel Marcus, Mar 22 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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