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 A067385 #16 Aug 22 2019 08:42:10 %S A067385 1,13,181,121679,1033474069 %N A067385 a(n) is smallest x such that sigma(phi(x))/sigma(x) = n. %C A067385 A023199(6) < a(6) <= 1794819234390989. - _Donovan Johnson_, Oct 24 2011 %t A067385 a[ n_ ] := For[ x=1, True, x++, If[ DivisorSigma[ 1, EulerPhi[ x ] ]/DivisorSigma[ 1, x ]==n, Return[ x ] ] ] %Y A067385 Cf. A023199, A033631, A066831, A067382, A067383, A067384, A197952. %K A067385 nonn,more %O A067385 1,2 %A A067385 _Dean Hickerson_, Jan 20 2002 %E A067385 a(5) from _Vim Wenders_, Mar 11 2007