A331176 a(n) = n - n/gcd(n, phi(n)), where phi is Euler totient function.

0, 0, 0, 2, 0, 3, 0, 6, 6, 5, 0, 9, 0, 7, 0, 14, 0, 15, 0, 15, 14, 11, 0, 21, 20, 13, 24, 21, 0, 15, 0, 30, 0, 17, 0, 33, 0, 19, 26, 35, 0, 35, 0, 33, 30, 23, 0, 45, 42, 45, 0, 39, 0, 51, 44, 49, 38, 29, 0, 45, 0, 31, 56, 62, 0, 33, 0, 51, 0, 35, 0, 69, 0, 37, 60, 57, 0, 65, 0, 75, 78, 41, 0, 77, 0, 43, 0, 77, 0, 75

Offset

1,4

Links

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

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

Formula

a(n) = n - A109395(n).

Mathematica

Table[n-n/GCD[n, EulerPhi[n]], {n, 90}] (* Harvey P. Dale, Aug 20 2020 *)

Prog

(PARI) A331176(n) = (n - (n/gcd(n, eulerphi(n))));

Crossrefs

Cf. A000010, A009195, A109395.

Cf. A003277 (indices of zeros).

Sequence in context: A348075 A130628 A249431 * A076563 A163974 A317443

Adjacent sequences: A331173 A331174 A331175 * A331177 A331178 A331179

Keyword

nonn

Author

Antti Karttunen, Jan 11 2020

Status

approved