A319988 a(n) = 1 if n is divisible by the square of its largest prime factor, 0 otherwise.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions

Formula

a(n) = 1 iff A071178(n) > 1.

a(n) = 1 if n > 1 and A006530(n)^2 divides n, otherwise 0.

a(n) = 1 iff n > 1 and A241917(n) = 0.

For n > 1, a(n) = A000035(A336124(n)) = A122111(n) mod 2. - Antti Karttunen, Jul 18 2020

Mathematica

Join[{0}, Table[If[Divisible[n, FactorInteger[n][[-1, 1]]^2], 1, 0], {n, 2, 130}]] (* Harvey P. Dale, Sep 19 2022 *)

Prog

(PARI) A319988(n) = ((n>1)&&(factor(n)[omega(n), 2]>1));

Crossrefs

Characteristic function of A070003.

Cf. A006530, A071178, A122111, A241917, A319710, A336124.

Sequence in context: A268340 A355453 A336356 * A023969 A060039 A319710

Adjacent sequences: A319985 A319986 A319987 * A319989 A319990 A319991

Keyword

nonn

Author

Antti Karttunen, Oct 04 2018

Status

approved