A373263 a(n) = 1 if A276085(n) == -1 (mod 3), otherwise 0, where A276085 is the primorial base log-function.

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

Offset

1

Links

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

Index entries for characteristic functions

Formula

a(n) = [A373153(n) = -1], where [ ] is the Iverson bracket.

a(n) = [A007949(n)-A007814(n) == +1 (mod 3)].

a(n) = 1 - (A372573(n)+A373260(n)).

Prog

(PARI) A373263(n) = (1==((valuation(n, 3)-valuation(n, 2))%3));
(PARI)
A002110(n) = prod(i=1, n, prime(i));
A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
A373263(n) = (2==(A276085(n)%3));

Crossrefs

Characteristic function of A373262.

Cf. A002110, A007814, A007949, A276085, A373153, A372573, A373260.

Sequence in context: A094754 A321694 A262684 * A287382 A074290 A091225

Adjacent sequences: A373260 A373261 A373262 * A373264 A373265 A373266

Keyword

nonn

Author

Antti Karttunen, May 30 2024

Status

approved