This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A064374 #14 Sep 27 2024 16:46:04
%S A064374 2,4,6,10,12,18,30
%N A064374 Numbers k such that sigma(k) > phi(k)^2.
%C A064374 Also numbers k such that sigma(k) > tau(k)*phi(k). - _Benoit Cloitre_, Aug 06 2002
%C A064374 There are no further terms. - _Benoit Cloitre_, Aug 06 2002
%F A064374 Solutions to A000203(k) > A000010(k)^2.
%e A064374 k = {2, 4, 6, 10, 12, 18, 30};
%e A064374 sigma(k) = {3, 7, 12, 18, 28, 39, 72};
%e A064374 phi(k) = {1, 2, 2, 4, 4, 6, 8};
%e A064374 phi(k)^2 = {1, 4, 4, 16, 16, 36, 64};
%e A064374 sigma(k) - phi(k)^2 = {2, 3, 8, 2, 12, 3, 8}.
%e A064374 No more solutions below 10000000.
%t A064374 Select[Range[30],DivisorSigma[1,#]>EulerPhi[#]^2&] (* _Harvey P. Dale_, Sep 27 2024 *)
%Y A064374 Cf. A000010, A000203, A055234.
%K A064374 nonn,fini,full
%O A064374 1,1
%A A064374 _Labos Elemer_, Sep 27 2001