A318829 a(n) = A063994(n) / A049559(n) = (1/gcd(n-1, phi(n))) * Product_{primes p dividing n} gcd(p-1, n-1).

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2

Offset

1,15

Comments

Records occur at: 1, 15, 85, 247, 671, 949, 1105, 1387, 2047, 2821, 9471, 11305, 13747, 13981, 29341, 40885, 51319, 63973, ...

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Formula

a(n) = A063994(n) / A049559(n).

a(n) = A160595(n) / A247074(n).

Prog

(PARI)
A049559(n) = gcd(eulerphi(n), n-1); \\ From A049559
A063994(n) = { my(f=factor(n)[, 1]); prod(i=1, #f, gcd(f[i]-1, n-1)); };
A318829(n) = (A063994(n)/A049559(n));

Crossrefs

Cf. A049559, A063994, A160595, A247074, A318828.

Sequence in context: A194309 A369936 A374326 * A113515 A103754 A375668

Adjacent sequences: A318826 A318827 A318828 * A318830 A318831 A318832

Keyword

nonn

Author

Antti Karttunen, Sep 09 2018

Status

approved