A318459 a(n) = gcd(n, tau(n), phi(n)), where tau = A000005 and phi = A000010.

1, 1, 1, 1, 1, 2, 1, 4, 3, 2, 1, 2, 1, 2, 1, 1, 1, 6, 1, 2, 1, 2, 1, 8, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2, 1, 8, 1, 2, 1, 2, 3, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 8, 1, 2, 1, 4, 1, 2, 3, 1, 1, 2, 1, 2, 1, 2, 1, 12, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 12, 1, 2, 1, 8, 1, 6, 1, 2, 1, 2, 1, 4, 1, 2, 3, 1, 1, 2, 1, 8, 1

Offset

1,6

Links

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

Formula

a(n) = gcd(n, A000005(n), A000010(n)).

a(n) = gcd(n,A009213(n)) = gcd(A000005(n),A009195(n)) = gcd(A000010(n),A009191(n)).

Mathematica

Table[GCD[n, DivisorSigma[0, n], EulerPhi[n]], {n, 110}] (* Harvey P. Dale, Jul 30 2019 *)

Prog

(PARI) A318459(n) = gcd([n, numdiv(n), eulerphi(n)]);

Crossrefs

Cf. A000005, A000010, A009191, A009195, A009213.

Cf. also A074389.

Sequence in context: A248929 A109977 A201199 * A300823 A345942 A175702

Adjacent sequences: A318456 A318457 A318458 * A318460 A318461 A318462

Keyword

nonn

Author

Antti Karttunen, Sep 07 2018, after Labos Elemer's A074389

Status

approved