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A308423
Product of divisors of multiply-perfect numbers.
2
1, 36, 21952, 42998169600000000, 30019840638976, 8480691722056324948490652657647616, 2343612817652433441167245312
OFFSET
1,2
COMMENTS
a(8) has 216 digits (116929951...000000000).
Supersequence of A067584.
LINKS
FORMULA
a(n) = A007955(A007691(n)).
EXAMPLE
For n = 3; a(3) = A007955(A007691(3)) = A007955(28) = 21952.
MATHEMATICA
s = {}; Do[If[Divisible[DivisorSigma[1, n], n], AppendTo[s, n^(DivisorSigma[0, n]/2)]], {n, 10^4}]; s (* Amiram Eldar, Jul 04 2019 *)
PROG
(Magma) [&*[d: d in Divisors(m)]: m in [1..10^5] | IsIntegral(SumOfDivisors(m)/m)]
CROSSREFS
See A088843 and A307741 for the number of and the sum of divisors of multiply-perfect numbers.
Sequence in context: A271338 A001308 A067584 * A146521 A159431 A028454
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, May 26 2019
STATUS
approved