%I #13 Apr 24 2020 11:02:20
%S 1,2,1285,2048,2056,2176,2560,2570,2720,3072,3084,3264,3840,4080,
%T 1114129,2097152,2097184,2105344,2228224,2228258,2236928,2621440,
%U 2621480,2631680,2785280,2796160,3145728,3145776,3158016,3342336
%N Numbers k such that phi(k) is a perfect tenth power.
%H Amiram Eldar, <a href="/A078170/b078170.txt">Table of n, a(n) for n = 1..2250</a>
%e phi of the sequence includes 1, 1024, 1048576,.. etc.; powers emerge several times; a(3) = A053576(10) = 1285; in sequence smoother ranges and quite large jumps alternate when power of new numbers appear as phi-values.
%t k=10; Do[s=EulerPhi[n]^(1/k); If[IntegerQ[s], Print[n]], {n, 1, 10000000}]
%o (PARI) is(n)=ispower(eulerphi(n),10) \\ _Charles R Greathouse IV_, Apr 24 2020
%Y Cf. A039770 (square), A039771 (cube), A078164 (4th), A078165 (5th), A078166 (6th), A078167 (7th), A078168 (8th), A078169 (9th), A078170 (10th power, this sequence), A001317, A053576, A045544, A000010.
%K nonn
%O 1,2
%A _Labos Elemer_, Nov 27 2002
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