OFFSET
1,2
LINKS
Wikipedia, Radical of an integer.
FORMULA
a(n) = Sum_{k=1..n} A176031(k).
EXAMPLE
a(4) = 48; a(4) = Sum_{k=1..4} k^rad(k) = 1^rad(1) + 2^rad(2) + 3^rad(3) + 4^rad(4) = 1^1 + 2^2 + 3^3 + 4^2 = 48.
MATHEMATICA
f[n_] := n^Times @@ FactorInteger[n][[;; , 1]]; Accumulate @ Array[f, 20] (* Amiram Eldar, Jan 29 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Jan 28 2022
STATUS
approved