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 A197952 #8 Mar 30 2012 17:35:03 %S A197952 1033474069,1604277377,2741806637,9941342981,14754456491,14859359791, %T A197952 15887724883,16990353761,17266051069,20892536447,21776951239, %U A197952 24435763193,25165559143,32325726313,38313868379,38580669727,38856433193,47906215417,49094416289,56237053007 %N A197952 Numbers n such that sigma(phi(n))/sigma(n) = 5. %e A197952 sigma(phi(25165559143))/sigma(25165559143) = 127671828480/25534365696 = 5. %o A197952 (PARI) for(n=1033474069, 3*10^10, if(sigma(eulerphi(n))/sigma(n)==5, print1(n, ", "))) %Y A197952 Cf. A033631, A066831, A067382, A067383, A067384, A067385. %K A197952 nonn %O A197952 1,1 %A A197952 _Donovan Johnson_, Oct 19 2011 %E A197952 a(14)-a(20) from _Donovan Johnson_, Nov 11 2011