A295314 a(n) = sigma(n) / gcd(sigma(n), phi(sigma(n))).

1, 3, 2, 7, 3, 3, 2, 15, 13, 3, 3, 7, 7, 3, 3, 31, 3, 13, 5, 7, 2, 3, 3, 15, 31, 7, 5, 7, 15, 3, 2, 7, 3, 3, 3, 91, 19, 15, 7, 15, 7, 3, 11, 7, 13, 3, 3, 31, 19, 31, 3, 7, 3, 15, 3, 15, 5, 15, 15, 7, 31, 3, 13, 127, 7, 3, 17, 7, 3, 3, 3, 65, 37, 19, 31, 35, 3, 7, 5, 31, 11, 7, 7, 7, 3, 33, 15, 15, 15, 13, 7, 7, 2, 3

Offset: 1

Author

Antti Karttunen, Nov 22 2017

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384

Crossrefs

Cf. A000010, A000203, A009195, A109395, A295313, A295315.

Programs

PARI

a(n) = my(sn = sigma(n)); sn/gcd(sn, eulerphi(sn)); \\ Michel Marcus, Nov 23 2017

Formula

a(n) = A000203(n) / A295313(n) = A109395(A000203(n)).