A373483 a(n) = 1 if A083345(n) and A276085(n) are both multiples of 3, otherwise 0, where A276085 is fully additive with a(p) = p#/p, and A083345 is the numerator of the fully additive function with a(p) = 1/p.

1, 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, 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, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 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, 1, 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, 1

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..100000

Index entries for characteristic functions

Formula

a(n) = A369643(n) * A372573(n).

a(n) = [A373485(n) == 0 (mod 3)], where [ ] is the Iverson bracket.

a(n) <= A373143(n).

Prog

(PARI)
A083345(n) = { my(f=factor(n)); numerator(vecsum(vector(#f~, i, f[i, 2]/f[i, 1]))); };
A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*prod(i=1, primepi(f[k, 1]-1), prime(i))); };
A373483(n) = (!(A083345(n)%3) && !(A276085(n)%3));

Crossrefs

Characteristic function of A373484.

Cf. A083345, A276085, A369643, A372573, A373143, A373485.

Sequence in context: A185118 A240332 A156297 * A373372 A373143 A373836

Adjacent sequences: A373480 A373481 A373482 * A373484 A373485 A373486

Keyword

nonn

Author

Antti Karttunen, Jun 09 2024

Status

approved