A373596 a(n) = 1 if n is a non-multiple of 3 whose multiplicies of prime factors of types 3m-1 and 3m+1 are both multiples of 3, otherwise 0.

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

Offset

1

Links

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

Index entries for characteristic functions

Prog

(PARI) A373596(n) = if(!(n%3) || bigomega(n)%3, 0, my(f = factor(n), m1=0, m2=0); for(i = 1, #f~, if(1==(f[i, 1]%3), m1 += f[i, 2], m2 += f[i, 2])); (0==(gcd(m1, m2)%3)));

Crossrefs

Characteristic function of A373597.

Differs from A373588 for the first time at n=343, where a(343) = 1, while A373588(343) = 0.

Differs from A373491 for the first time at n=1323, where a(1323) = 0, while A373491(1323) = 1.

Cf. also A353557 (roughly analogous sequence for k=2, instead of k=3).

Sequence in context: A014744 A373491 A373588 * A373472 A373493 A014646

Adjacent sequences: A373593 A373594 A373595 * A373597 A373598 A373599

Keyword

nonn

Author

Antti Karttunen, Jun 10 2024

Status

approved