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A076402
Euler's totient of n-th perfect power.
1
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
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
Sequence in context: A329738 A133296 A323333 * A053198 A249278 A273892
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Oct 09 2002
STATUS
approved