A076402 Euler's totient of n-th perfect power.

1, 2, 4, 6, 8, 20, 18, 16, 12, 42, 32, 54, 40, 110, 100, 64, 48, 156, 84, 72, 120, 162, 128, 272, 108, 294, 342, 160, 252, 220, 256, 506, 192, 500, 312, 486, 336, 812, 240, 930, 400, 512, 660, 544, 840, 432, 1210, 1332, 684, 936, 640, 1640, 576, 504, 1806, 880

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Perfect Powers.

Eric Weisstein's World of Mathematics, Totient Function.

Formula

a(n) = A000010(A001597(n)).

Mathematica

powQ[n_] := GCD @@ FactorInteger[n][[;; , 2]] > 1; EulerPhi[Join[{1}, Select[Range[2000], powQ]]] (* Amiram Eldar, Feb 29 2020 *)

Crossrefs

Cf. A000010, A001597.

Sequence in context: A329738 A133296 A323333 * A053198 A249278 A273892

Adjacent sequences: A076399 A076400 A076401 * A076403 A076404 A076405

Keyword

nonn

Author

Reinhard Zumkeller, Oct 09 2002

Status

approved