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%I #15 Jun 12 2022 02:58:49
%S 2,3,4,6,8,10,12,14,16,18,20,24,30,36,40,42,48,60,72,84,90,120,180
%N Numbers k such that tau(k)*sigma(k) > k*phi(k).
%C Numbers k such that A064840(k) > A002618(k).
%t Select[Range[180], DivisorSigma[0, #] * DivisorSigma[1, #] > # * EulerPhi[#] &] (* _Amiram Eldar_, Jun 12 2022 *)
%o (PARI) is(k) = {my(f=factor(k)); numdiv(k)*sigma(k) > k*eulerphi(k); } \\ _Jinyuan Wang_, Apr 05 2020
%Y Cf. A000005, A000010, A000203, A002618, A064840.
%K nonn,easy,fini,full
%O 1,1
%A _Benoit Cloitre_, Mar 26 2002