A076292 Perfect powers with squarefree root.

1, 4, 8, 9, 16, 25, 27, 32, 36, 49, 64, 81, 100, 121, 125, 128, 169, 196, 216, 225, 243, 256, 289, 343, 361, 441, 484, 512, 529, 625, 676, 729, 841, 900, 961, 1000, 1024, 1089, 1156, 1225, 1296, 1331, 1369, 1444, 1521, 1681, 1764, 1849, 2048, 2116, 2187

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

A025478(a(n)) = A007947(a(n)).

Example

A001597(17) = 144 = (3*2^2)^2 is not a term.

Mathematica

q[n_] := n == 1 || Length[(u = Union[FactorInteger[n][[;; , 2]]])] == 1 && u[[1]] > 1; Select[Range[2000], q] (* Amiram Eldar, Jan 01 2022 *)

Prog

(PARI) is(n)=n==1 || (ispower(n, , &n) && issquarefree(n)) \\ Charles R Greathouse IV, Oct 16 2015

Crossrefs

Cf. A001597, A025478, A005117, A007947, A072777.

Sequence in context: A001597 A359493 A072777 * A090516 A090515 A075309

Adjacent sequences: A076289 A076290 A076291 * A076293 A076294 A076295

Keyword

nonn

Author

Reinhard Zumkeller, Nov 06 2002

Status

approved