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 A319691 a(n) = 1 if n is either 1 or divisible only by primes congruent to 1 mod 3, 0 otherwise. 3
 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(n) = A319690(n) mod 2. Fully multiplicative with a(p) = 1 if p is a prime of the form 3k+1, otherwise a(p) = 0. PROG (PARI) A319691(n) = factorback(apply(p -> ((p%3)%2), factor(n)[, 1])); CROSSREFS Characteristic function of A004611. Cf. A319690. Sequence in context: A015989 A267417 A014189 * A079979 A288711 A089010 Adjacent sequences:  A319688 A319689 A319690 * A319692 A319693 A319694 KEYWORD nonn,mult AUTHOR Antti Karttunen, Oct 04 2018 STATUS approved

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Last modified January 23 19:36 EST 2020. Contains 331175 sequences. (Running on oeis4.)