A373361 a(n) = gcd(n, A276085(n)), where A276085 is the primorial base log-function.

1, 1, 1, 2, 1, 3, 1, 1, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 3, 4, 1, 3, 1, 1, 1, 1, 1, 6, 1, 19, 1, 1, 1, 3, 1, 4, 5, 1, 1, 6, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 10, 1, 1, 1, 2, 1, 3, 1, 4, 1, 1, 1, 1, 1, 1, 1, 4, 1, 3, 1, 10, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 13, 4, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 1, 1, 1

Offset: 1

Author

Antti Karttunen, Jun 02 2024

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• Index entries for sequences related to primorial numbers

Crossrefs

Cf. A002110, A276085.

Cf. A108269 (positions of even terms), A328981 (their characteristic function), A359794 (positions of odd terms), A359832 (their characteristic function, parity of terms).

Cf. also A324198, A373145, A373362.

Programs

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)); };
A373361(n) = gcd(n, A276085(n));