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 A062374 #15 Jun 24 2022 05:33:30
%S A062374 24,40,48,56,60,65,72,84,85,88,96,104,105,112,130,132,136,140,144,145,
%T A062374 152,156,165,170,176,180,184,185,192,200,204,205,210,216,220,221,224,
%U A062374 228,231,232,248,265,276,285,288,290,296,300,304,305,308,325,328,330
%N A062374 Euler phi(n) / Carmichael lambda(n) = 4.
%C A062374 Solutions to A000010(n)/A002322(n)=4.
%H A062374 R. J. Mathar, <a href="/A062374/b062374.txt">Table of n, a(n) for n = 1..20000</a>
%t A062374 Select[Range[400],EulerPhi[#]/CarmichaelLambda[#]==4&] (* _Harvey P. Dale_, May 23 2011 *)
%o A062374 (PARI) {cmf(f)=if( ((f[1]==2)&&(f[2]>2)),eulerphi(f[1]^f[2])/2, eulerphi(f[1]^f[2])) } {cl(f)= k=factor(f); l=1; for(x=1,omega(f),l=lcm(l,cmf([k[x,1], k[x,2]]))); l } {A062374(n)=eulerphi(n)/cl(n)} for(x=1,10001, if(A062374(x)==4,print1(x,",")))
%Y A062374 Cf. A000010, A002322, A034380, A033948, A062373, A062375, A062376, A062377.
%K A062374 easy,nonn
%O A062374 1,1
%A A062374 _Vladeta Jovovic_, Jun 17 2001
%E A062374 More terms from _Randall L Rathbun_, Jan 12 2002