A062374 Euler phi(n) / Carmichael lambda(n) = 4.

24, 40, 48, 56, 60, 65, 72, 84, 85, 88, 96, 104, 105, 112, 130, 132, 136, 140, 144, 145, 152, 156, 165, 170, 176, 180, 184, 185, 192, 200, 204, 205, 210, 216, 220, 221, 224, 228, 231, 232, 248, 265, 276, 285, 288, 290, 296, 300, 304, 305, 308, 325, 328, 330

Offset: 1

Author

Vladeta Jovovic, Jun 17 2001

Keywords

• easy
• nonn

Comments

Solutions to A000010(n)/A002322(n)=4.

Links

• R. J. Mathar, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A000010, A002322, A034380, A033948, A062373, A062375, A062376, A062377.

Programs

Mathematica

Select[Range[400],EulerPhi[#]/CarmichaelLambda[#]==4&] (* Harvey P. Dale, May 23 2011 *)

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,",")))

Extensions

More terms from Randall L Rathbun, Jan 12 2002