A340678 a(n) = A008472(n) / gcd(A007947(n), A008472(n)).

0, 1, 1, 1, 1, 5, 1, 1, 1, 7, 1, 5, 1, 9, 8, 1, 1, 5, 1, 7, 10, 13, 1, 5, 1, 15, 1, 9, 1, 1, 1, 1, 14, 19, 12, 5, 1, 21, 16, 7, 1, 2, 1, 13, 8, 25, 1, 5, 1, 7, 20, 15, 1, 5, 16, 9, 22, 31, 1, 1, 1, 33, 10, 1, 18, 8, 1, 19, 26, 1, 1, 5, 1, 39, 8, 21, 18, 3, 1, 7, 1, 43, 1, 2, 22, 45, 32, 13, 1, 1, 20, 25, 34, 49, 24, 5, 1, 9

Offset: 1

Author

Antti Karttunen, Feb 01 2021

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384
• Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537

Crossrefs

Cf. A007947, A008472, A099636, A340677.

Cf. also A082343.

Programs

PARI

A007947(n) = factorback(factorint(n)[, 1]);
A008472(n) = vecsum(factor(n)[, 1]);
A340678(n) = { my(v=A008472(n)); (v/gcd(A007947(n), v)); };

Formula

a(n) = A008472(n) / A099636(n) = A008472(n) / gcd(A007947(n), A008472(n)).