A373383 a(n) = 1 if n and A059975(n) are both multiples of 3, otherwise 0, where A059975 is fully additive with a(p) = p-1.

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

Offset

1

Comments

Question: What is the asymptotic mean of this sequence?

Links

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

Index entries for characteristic functions

Formula

a(n) = [A373368(n) == 0 (mod 3)], where [ ] is the Iverson bracket.

Prog

(PARI)
A059975(n) = {my(f = factor(n)); sum(i = 1, #f~, f[i, 2]*(f[i, 1] - 1)); };
A373383(n) = !(gcd(n, A059975(n))%3);

Crossrefs

Characteristic function of A373384.

Cf. A059975, A373368.

Sequence in context: A378537 A379475 A302049 * A078926 A324824 A025458

Adjacent sequences: A373380 A373381 A373382 * A373384 A373385 A373386

Keyword

nonn

Author

Antti Karttunen, Jun 06 2024

Status

approved