A330682 - OEIS

A330682

a(n) = 1 if the 2-adic and 3-adic valuations of A025487(n) are equal, 0 otherwise.

1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 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, 1, 1, 0, 0, 0, 1, 0, 1, 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, 1, 0, 0, 0, 1, 0, 0

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OFFSET

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..47617

Index entries for characteristic functions.

FORMULA

a(n) = [A007814(A025487(n)) == A007949(A025487(n))], where [ ] is the Iverson bracket.

a(n) = A000035(A181815(n)) = A181815(n) mod 2.

a(A329897(n)) = 1, a(A329898(n)) = 0.

MATHEMATICA

s = {1}; Do[If[GreaterEqual @@ (f = FactorInteger[n])[[;; , 2]] && PrimePi[f[[-1, 1]]] == Length[f], AppendTo[s, If[Equal @@ IntegerExponent[n, {2, 3}], 1, 0]]], {n, 2, 50000}]; s (* Amiram Eldar, Jul 27 2023 *)

PROG

(PARI) A330682(n) = (A181815(n)%2);

CROSSREFS

Characteristic function of A329897.

Cf. A007814, A007949, A025487, A181815, A329898.

Sequence in context: A304362 A368997 A373830 * A230135 A359836 A359835

Adjacent sequences: A330679 A330680 A330681 * A330683 A330684 A330685

KEYWORD

nonn

AUTHOR

Antti Karttunen, Dec 24 2019

STATUS

approved