A354871 a(n) = gcd(A056239(n), A258851(n)).

0, 1, 2, 2, 3, 1, 4, 3, 4, 1, 5, 4, 6, 5, 1, 4, 7, 1, 8, 1, 2, 3, 9, 1, 6, 1, 6, 2, 10, 1, 11, 5, 1, 1, 1, 6, 12, 1, 4, 6, 13, 1, 14, 1, 1, 1, 15, 2, 8, 1, 1, 4, 16, 1, 2, 1, 2, 1, 17, 1, 18, 1, 8, 6, 3, 1, 19, 3, 1, 1, 20, 1, 21, 1, 4, 2, 1, 1, 22, 1, 8, 1, 23, 4, 2, 1, 4, 4, 24, 1, 2, 1, 1, 1, 1, 1, 25, 1, 3, 4

Offset: 1

Author

Antti Karttunen, Jun 11 2022

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• Index entries for sequences computed from indices in prime factorization

Crossrefs

Cf. A056239, A258851, A278510, A354872, A354873.

Programs

PARI

A056239(n) = { my(f); if(1==n, 0, f=factor(n); sum(i=1, #f~, f[i, 2] * primepi(f[i, 1]))); }
A258851(n) = (n*sum(i=1, #n=factor(n)~, n[2, i]*primepi(n[1, i])/n[1, i])); \\ From A258851
A354871(n) = gcd(A056239(n), A258851(n));

Formula

a(n) = gcd(A056239(n), A258851(n)).

a(n) = gcd(A056239(n), A278510(n)) = gcd(A258851(n), A278510(n)).

For n > 1, a(n) = A056239(n) / A354872(n) = A258851(n) / A354873(n).