OFFSET
1,1
COMMENTS
Next term is greater than 65*10^6.
241287413760 and 6094936793088000 are also terms - Donovan Johnson, Aug 08 2012
EXAMPLE
62000640 is in the sequence because sigma(62000640)-62000640 = 187545888 and phi(187545888) = 62000640.
MATHEMATICA
Do[If[n == EulerPhi[DivisorSigma[1, n]-n], Print[n]], {n, 65000000}]
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Farideh Firoozbakht, May 26 2005
EXTENSIONS
a(7) from Donovan Johnson, Oct 12 2008
a(8) from Donovan Johnson, Aug 08 2012
STATUS
approved