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A323239 a(n) = 1 if n is odd and squarefree, otherwise a(n) = 0. 3
0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0

COMMENTS

Characteristic function of A056911.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..65537

Index entries for characteristic functions

FORMULA

a(n) = A000035(n) * A008966(n).

For n >= 1:

a(n) = abs(A087003(n)) = abs(A099991(n)).

a(n) = A085405(A156552(n)).

MAPLE

f:= n -> charfcn[{true}](n::odd and numtheory:-issqrfree(n)):

map(f, [$0..200]); # Robert Israel, Jan 14 2019

PROG

(PARI) A323239(n) = ((n%2) && issquarefree(n));

CROSSREFS

Absolute values of A087003 and A099991.

Cf. A000035, A008966, A056911, A085405, A156552, A322810.

Sequence in context: A215532 A191152 A139312 * A285685 A287773 A173923

Adjacent sequences:  A323236 A323237 A323238 * A323240 A323241 A323242

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jan 12 2019

STATUS

approved

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Last modified September 26 05:00 EDT 2020. Contains 337346 sequences. (Running on oeis4.)