A064447 a(n) = EulerPhi(n^n).

1, 2, 18, 128, 2500, 15552, 705894, 8388608, 258280326, 4000000000, 259374246010, 2972033482752, 279577021469772, 4762288639524864, 233543408203125000, 9223372036854775808, 778579070010669895696, 13115469358432179191808, 1874292305362402347591138

Offset

1,2

Links

Harry J. Smith, Table of n, a(n) for n = 1..100

Formula

a(n) = A000010(A000312(n)).

Example

For p prime, a(p) = (p^(p-1))*(p-1) = ((phi(p)+1)^phi(p))*phi(p).

Mathematica

a[n_]:=EulerPhi[n^n]; lst={}; Do[AppendTo[lst, a[n]], {n, 0, 2*4!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 03 2008 *)
Table[EulerPhi[n^n], {n, 20}] (* Harvey P. Dale, Jun 02 2015 *)

Prog

(PARI) { for (n=1, 100, write("b064447.txt", n, " ", eulerphi(n^n)) ) } \\ Harry J. Smith, Sep 14 2009

Crossrefs

Cf. A000005, A000010, A000312.

Sequence in context: A277661 A367553 A363662 * A043022 A057971 A360132

Adjacent sequences: A064444 A064445 A064446 * A064448 A064449 A064450

Keyword

nonn

Author

Labos Elemer, Oct 02 2001

Status

approved