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A355946
a(n) = 1 if the odd part of sigma(k) divides A003961(k), otherwise 0, where A003961 is fully multiplicative with a(p) = nextprime(p), and sigma is the sum of divisors function.
3
1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1
OFFSET
1
FORMULA
a(n) = [0 == A003961(n) mod A161942(n)] = [0 == n mod A350073(n)], where [ ] is the Iverson bracket.
PROG
(PARI)
A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A355946(n) = { my(s=sigma(n)); !(A003961(n)%((s>>=valuation(s, 2)))); };
CROSSREFS
Characteristic function of A349756.
Cf. also A355943.
Sequence in context: A145379 A258869 A128810 * A123272 A266623 A359579
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 23 2022
STATUS
approved