A318828 a(n) = n - A063994(n) = n - Product_{primes p dividing n} gcd(p-1, n-1).

0, 1, 1, 3, 1, 5, 1, 7, 7, 9, 1, 11, 1, 13, 11, 15, 1, 17, 1, 19, 17, 21, 1, 23, 21, 25, 25, 25, 1, 29, 1, 31, 29, 33, 31, 35, 1, 37, 35, 39, 1, 41, 1, 43, 37, 45, 1, 47, 43, 49, 47, 49, 1, 53, 51, 55, 53, 57, 1, 59, 1, 61, 59, 63, 49, 61, 1, 67, 65, 67, 1, 71, 1, 73, 71, 73, 73, 77, 1, 79, 79, 81, 1, 83, 69, 85, 83, 87, 1, 89, 55

Offset

1,4

Links

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

Formula

a(n) = n - A063994(n).

Prog

(PARI)
A063994(n) = { my(f=factor(n)[, 1]); prod(i=1, #f, gcd(f[i]-1, n-1)); }; \\ From A063994
A318828(n) = (n-A063994(n));

Crossrefs

Cf. A063994, A318827, A318829.

Sequence in context: A147410 A146623 A197943 * A318827 A339236 A029669

Adjacent sequences: A318825 A318826 A318827 * A318829 A318830 A318831

Keyword

nonn

Author

Antti Karttunen, Sep 09 2018

Status

approved