A068212 a(n) = phi(n) divided by its largest prime factor.

1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 4, 2, 4, 4, 8, 2, 6, 4, 4, 2, 2, 4, 4, 4, 6, 4, 4, 4, 6, 8, 4, 8, 8, 4, 12, 6, 8, 8, 8, 4, 6, 4, 8, 2, 2, 8, 6, 4, 16, 8, 4, 6, 8, 8, 12, 4, 2, 8, 12, 6, 12, 16, 16, 4, 6, 16, 4, 8, 10, 8, 24, 12, 8, 12, 12, 8, 6, 16, 18, 8, 2, 8, 32, 6, 8, 8, 8, 8, 24, 4, 12, 2, 24

Offset: 3

Author

Labos Elemer, Feb 21 2002

Keywords

• nonn

Crossrefs

Cf. A000010, A006530, A052126, A068211.

Programs

Mathematica

epn[n_]:=Module[{e=EulerPhi[n]},e/FactorInteger[e][[-1,1]]]; Array[ epn,100,3] (* Harvey P. Dale, Apr 18 2012 *)

Formula

a(n) = A052126(A000010(n)) = A000010(n)/A068211(n) = A000010(n)/A006530(A000010(n)).