A132349 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

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Mathematica

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

Prog

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

Crossrefs

Cf. A132350, A132351, A132352, A132384.

Sequence in context: A355524 A113503 A082507 * A216226 A123391 A375339

Adjacent sequences: A132346 A132347 A132348 * A132350 A132351 A132352

Keyword

nonn

Author

N. J. A. Sloane, Nov 11 2007

Status

approved