reviewed

approved

proposed

reviewed

editing

proposed

a[n_] := Boole[(g = GCD @@ FactorInteger[n][[;; , 2]]) > 1] * g; Array[a, 100] (* Amiram Eldar, Aug 13 2024 *)

(PARI) r(n) = for(j=1, n, print1(ispower(j)", ")); r(100))", "));

r(100)

Cf. A132384-A132350, A132351, A132352, A132384.

approved

editing

proposed

approved

editing

proposed

Antti Karttunen, <a href="/A132349/b132349.txt">Table of n, a(n) for n = 1..10000</a>

approved

editing

_N. J. A. Sloane (njas(AT)research.att.com), _, Nov 11 2007

OEIS Server: https://oeis.org/edit/global/110

nonn,new

nonn

N. J. A. Sloane (njas, (AT)research.att.com), Nov 11 2007

If n is a k-th power with k >= 2 then a(n) = k, otherwise a(n) = 0.

0, 0, 0, 2, 0, 0, 0, 3, 2, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 3, 0, 0, 0, 0, 5, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2

1,4

(PARI) r(n) = for(j=1, n, print1(ispower(j)", ")); r(100)

Cf. A132384-A132352.

nonn,new

njas, Nov 11 2007

approved