A295315 a(n) = phi(sigma(n)) / gcd(sigma(n), phi(sigma(n))).

1, 2, 1, 6, 1, 1, 1, 8, 12, 1, 1, 3, 3, 1, 1, 30, 1, 8, 2, 2, 1, 1, 1, 4, 30, 2, 2, 3, 4, 1, 1, 4, 1, 1, 1, 72, 9, 4, 3, 4, 2, 1, 5, 2, 4, 1, 1, 15, 12, 20, 1, 3, 1, 4, 1, 4, 2, 4, 4, 2, 15, 1, 6, 126, 2, 1, 8, 2, 1, 1, 1, 32, 18, 6, 15, 12, 1, 2, 2, 10, 10, 2, 2, 3, 1, 10, 4, 4, 4, 4, 3, 2, 1, 1, 4, 2, 3, 12, 4

Offset

1,2

Links

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

Formula

a(n) = A062401(n) / A295313(n) = A062401(n) / A009195(A000203(n)).

a(n) = A076512(A000203(n)).

Prog

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

Crossrefs

Cf. A000010, A000203, A009195, A062401, A076512, A295312, A295313, A295314.

Sequence in context: A208682 A094673 A196839 * A089808 A290318 A139547

Adjacent sequences: A295312 A295313 A295314 * A295316 A295317 A295318

Keyword

nonn

Author

Antti Karttunen, Nov 22 2017

Status

approved