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A358775
a(n) = 1 if the prime factorization of n has an even number of prime factors that sum to an odd number, otherwise 0.
3
0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0
OFFSET
1
FORMULA
a(n) = A065043(n) * A000035(A007814(n)).
a(n) = A065043(n) * (1-A356163(n)).
a(n) = A065043(n) - A353374(n).
PROG
(PARI) A358775(n) = (!(bigomega(n)%2) * (valuation(n, 2)%2));
(PARI) A358775(n) = if(bigomega(n)%2, 0, my(f = factor(n)); 1==((sum(i=1, #f~, f[i, 2]*f[i, 1]))%2));
CROSSREFS
Characteristic function of A358776.
Sequence in context: A011673 A361463 A104853 * A354981 A231600 A347579
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 01 2022
STATUS
approved