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%I #15 Oct 24 2020 04:11:47
%S 16,32,64,81,128,243,256,512,625,729,1024,2048,2187,2401,3125,4096,
%T 6561,8192,14641,15625,16384,16807,19683,28561,32768,59049,65536,
%U 78125,83521,117649,130321,131072,161051,177147,262144,279841,371293,390625,524288,531441,707281,823543,923521,1048576,1419857,1594323,1771561
%N Prime powers p^e where p is a prime and e >= 4.
%H Jens Kruse Andersen, <a href="/A246550/b246550.txt">Table of n, a(n) for n = 1..10000</a>
%F Sum_{n>=1} 1/a(n) = Sum_{p prime} 1/(p^3*(p-1)) = 0.1461466097... - _Amiram Eldar_, Oct 24 2020
%p N:= 10^7: # to get all terms <= N
%p {seq(seq(p^m, m=4..floor(log[p](N))), p = select(isprime,[2,seq(2*i+1,i=1..floor(N^(1/4)))]))}; # _Robert Israel_, Aug 29 2014
%t With[{max = 10^6}, Sort @ Flatten @ Table[p^Range[4, Floor[Log[p, max]]], {p, Select[Range[Surd[max, 4]], PrimeQ]}]] (* _Amiram Eldar_, Oct 24 2020 *)
%o (PARI) m=10^7; v=[]; forprime(p=2, m^(1/4), e=4; while(p^e<=m, v=concat(v, p^e); e++)); v=vecsort(v) \\ _Jens Kruse Andersen_, Aug 29 2014
%Y Cf. A000961, A246547, A246549, A168363.
%K nonn
%O 1,1
%A _Joerg Arndt_, Aug 29 2014
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