%I #17 May 08 2021 22:57:10
%S 1,2,8,9,18,64,72,128,625,729,1024,1152,1250,1458,4096,5000,5625,5832,
%T 6561,8192,9216,11250,13122,15625,31250,32768,40000,45000,46656,52488,
%U 59049,65536,80000,93312,117649,118098,125000,235298,262144,294912
%N Numbers k such that the number of divisors of k and sum of 4th powers of divisors of k are relatively prime.
%C It can be shown that this is a subsequence of A028982.
%H Amiram Eldar, <a href="/A046681/b046681.txt">Table of n, a(n) for n = 1..5000</a>
%t Select[Range[300000],CoprimeQ[DivisorSigma[0,#],DivisorSigma[4,#]]&] (* _Harvey P. Dale_, May 30 2012 *)
%o (PARI) isok(n) = gcd(sigma(n, 4), numdiv(n)) == 1; \\ _Michel Marcus_, Sep 24 2019
%Y Cf. A028982, A046678, A046679, A046680, A046683, A046685.
%K nonn
%O 1,2
%A _Labos Elemer_