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A325964 a(n) = 1 if n and sigma(n) are relatively prime, 0 otherwise, where sigma(n) = sum of divisors of n, A000203; Characteristic function of A014567. 4
1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 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, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1
LINKS
FORMULA
a(n) = 1 if gcd(n, sigma(n)) [= A009194(n)] is 1, 0 otherwise.
PROG
(PARI) A325964(n) = (1==gcd(n, sigma(n)));
CROSSREFS
Cf. also A297086, A322980.
Sequence in context: A340375 A010055 A324290 * A344885 A345064 A076699
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 29 2019
STATUS
approved

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Last modified July 3 20:08 EDT 2024. Contains 373986 sequences. (Running on oeis4.)