OFFSET
1,1
COMMENTS
This is a subsequence of A007955, product of divisors of n.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..8
FORMULA
EXAMPLE
a(2) = 21952 because a(2) = 1*2*4*7*14*28=21952 (= 28^3) is the product of all (3*2) divisors of the 2nd perfect number, 28 (= 2^(3-1) * (2^3 - 1)).
a(6), a 169 decimal digit number (= 8589869056^17), is the product of all (17*2) divisors of the 6th perfect number, 8589869056 (= 2^(17-1) * (2^17 - 1)).
MATHEMATICA
f[n_] := n^(DivisorSigma[0, n]/2); f /@ PerfectNumber[Range[5]] (* Amiram Eldar, Oct 17 2024 *)
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Rick L. Shepherd, Jan 31 2002
STATUS
approved