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A373153
a(n) is -1, 0, or 1 such that a(n) == A276085(n) (mod 3), where A276085 is the primorial base log-function.
8
0, 1, -1, -1, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, -1, 1, 0, -1, 0, -1, -1, 1, 0, -1, 0, 1, 0, -1, 0, 0, 0, -1, -1, 1, 0, 0, 0, 1, -1, 0, 0, 0, 0, -1, 1, 1, 0, 0, 0, 1, -1, -1, 0, 1, 0, 0, -1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, -1, -1, 1, 0, 1, 0, 1, -1, -1, 0, 0, 0, 1, -1, 1, 0, 1, 0, 1, -1, 0, 0, -1, 0, -1, -1, 1, 0, 1, 0, 1, 1, -1, 0, 0, 0, 0, -1
OFFSET
1
COMMENTS
Completely additive modulo 3.
a(n) is -1, 0, or 1 such that a(n) == A007814(n)-A007949(n) (mod 3). - Antti Karttunen, Jun 01 2024
PROG
(PARI)
A002110(n) = prod(i=1, n, prime(i));
A373153(n) = { my(f = factor(n), u); u=sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1))%3; if(2==u, -1, u); };
(PARI) A373153(n) = { my(u=(valuation(n, 2)-valuation(n, 3))%3); if(2==u, -1, u); }; \\ Antti Karttunen, Jun 01 2024
CROSSREFS
Cf. A339746 (positions of 0's), A373261 (of +1's), A373262 (of -1's).
Cf. also A332814, A332823, A373253.
Sequence in context: A138712 A029693 A200263 * A051067 A288858 A356313
KEYWORD
sign
AUTHOR
Antti Karttunen, May 27 2024
STATUS
approved