A355818 Greatest common divisor of n, sigma(n) and A276086(n), where A276086 is primorial base exp-function.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 1, 1, 3, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 3

Offset: 1

Author

Antti Karttunen, Jul 19 2022

Keywords

• nonn

Links

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

Crossrefs

Sequence contains only terms of A048103.

Cf. A000203, A009194, A276086, A324198, A324644.

Cf. also A355815, A327858, A355456.

Programs

PARI

A009194(n) = gcd(n, sigma(n));
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A355818(n) = gcd(A009194(n), A276086(n));

Formula

a(n) = gcd(n, A324644(n)) = gcd(A000203(n), A324198(n)) = gcd(A009194(n), A276086(n)).

a(n) = gcd(A009194(n), A324198(n)).