OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Range[1, 10^3], EulerPhi[DivisorSigma[1, EulerPhi[ # ]]] == EulerPhi[ # ] &]
PROG
(PARI) { n=0; for (m=1, 10^10, if (eulerphi(sigma(eulerphi(m))) == eulerphi(m), write("b066463.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Feb 16 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Jan 02 2002
STATUS
approved