OFFSET
1,2
LINKS
EXAMPLE
a(54) = 15 because 54 = 2 * 3^3 = prime(1) * prime(2)^3 and prime(prime(1)) * prime(prime(2)) = 3 * 5 = 15.
MATHEMATICA
a[n_] := Times @@ (Prime[#[[1]]] & /@ FactorInteger[n]); Table[a[n], {n, 1, 65}]
PROG
(PARI) a(n)={my(f=factor(n)[, 1]); prod(i=1, #f, prime(f[i]))} \\ Andrew Howroyd, Oct 29 2019
CROSSREFS
KEYWORD
nonn,mult
AUTHOR
Ilya Gutkovskiy, Oct 29 2019
STATUS
approved