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A075802 Characteristic function of perfect powers, A001597. 15
1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Not multiplicative: for example, a(8)=a(9)=1, but a(72)=0. - Franklin T. Adams-Watters, Sep 09 2005

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Perfect Powers.

Index entries for characteristic functions

FORMULA

a(n) = A057427(A052409(n) - 1);

a(A001597(n))=1 and a(A007916(n))=0.

MATHEMATICA

a[n_] := Boole[GCD @@ FactorInteger[n][[All, 2]] > 1]; a[1] = 1; Table[a[n], {n, 1, 105}] (* Jean-Fran├žois Alcover, Dec 12 2011 *)

PROG

(Haskell)

a075802 1 = 1

a075802 n = signum $ a052409 n - 1  -- Reinhard Zumkeller, May 26 2012

CROSSREFS

Cf. A112526.

Cf. A072292.

Sequence in context: A170956 A293449 A307424 * A307423 A112526 A120523

Adjacent sequences:  A075799 A075800 A075801 * A075803 A075804 A075805

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Oct 13 2002

STATUS

approved

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Last modified November 21 22:16 EST 2019. Contains 329383 sequences. (Running on oeis4.)