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A353669
a(n) = 1 if n is a nonsquare that has an even number of prime factors with multiplicity, otherwise 0.
2
0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0
OFFSET
1
FORMULA
a(n) = if A001222(n) and A000005(n) are both even, otherwise 0.
a(n) = A065043(n) - A010052(n).
MATHEMATICA
Table[If[!IntegerQ[Sqrt[n]]&&EvenQ[PrimeOmega[n]], 1, 0], {n, 150}] (* Harvey P. Dale, Sep 19 2022 *)
PROG
(PARI) A353669(n) = (!issquare(n) && !(bigomega(n)%2));
(PARI) A353669(n) = (0==((bitxor(bigomega(n), numdiv(n)))%2));
CROSSREFS
Characteristic function of A119899.
Sequence in context: A347579 A280710 A354353 * A363915 A353671 A353672
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 04 2022
STATUS
approved