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 A064377 #7 Aug 20 2021 15:17:43 %S A064377 2,3,4,6,8,10,12,14,15,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44, %T A064377 48,50,54,56,60,66,70,72,78,80,84,90,96,100,102,108,110,114,120,126, %U A064377 130,132,138,140,144,150,156,162,168,174,180,186,192,198,204,210,216,222,228,234,240,246,252,258,264,270,276,282,294,300,306,312,330,336,342,360,378,390,396,420,450,462,480,504,510,540,546,570,600,630,660,690,714,720,750,780,840,870,930,990,1020,1050,1170,1260,1470,1680,2310 %N A064377 Numbers n such that sigma_4(n) > phi(n)^5. %C A064377 It is conjectured that there are no other solutions. %C A064377 This sequence is finite, since by Grönwall's theorem sigma_4(n) <= sigma(n)^4 << (n log log n)^4 but phi(n)^5 >> (n/log log n)^5. - _Charles R Greathouse IV_, Nov 19 2015 %F A064377 Solutions to A001159(n) > phi(n)^5. %t A064377 Select[Range[2400],DivisorSigma[4,#]>EulerPhi[#]^5&] (* _Harvey P. Dale_, Aug 20 2021 *) %o A064377 (PARI) is(n)=my(f=factor(n)); sigma(f, 4)>eulerphi(f)^5 \\ _Charles R Greathouse IV_, Nov 19 2015 %Y A064377 Cf. A001159, A000010. %K A064377 nonn,fini,full %O A064377 1,1 %A A064377 _Labos Elemer_, Sep 27 2001