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A280582
a(n) = the product of divisors of product of divisors of n.
3
1, 2, 3, 64, 5, 10077696, 7, 2097152, 729, 1000000000, 11, 2116471057875484488839167999221661362284396544, 13, 20661046784, 38443359375, 36028797018963968, 17, 52655678627806560751363688397557640770141543227981824, 19
OFFSET
1,2
FORMULA
a(n) = A007955(A007955(n)).
For p = primes (A000040); a(p) = p.
For c = composites (A002808); a(c) = perfect powers of the form m^k where m > 1 and k >= 2 (terms of A001597).
EXAMPLE
For n = 4; a(n) = product of divisors (1*2*4) = 1*2*4*8 = 64.
MATHEMATICA
Table[Nest[Times @@ Divisors@ # &, n, 2], {n, 19}] (* Michael De Vlieger, Jan 06 2017 *)
PROG
(Magma) [&*[d: d in Divisors(&*[d: d in Divisors(n)])]: n in [1..100]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 06 2017
STATUS
approved