OFFSET
1,1
EXAMPLE
sigma(915-phi(915)) = sigma(915-480) = 720; phi(915+phi(915)) = phi(1395) = 720, so 915 is a term of the sequence.
MATHEMATICA
r = {}; Do[e = EulerPhi[n]; If[DivisorSigma[1, n - e] == EulerPhi[n + e], r = Append[r, n]], {n, 1, 10^5}]; r
Select[Range[3000000], DivisorSigma[1, #-EulerPhi[#]]==EulerPhi[#+ EulerPhi[ #]]&] (* Harvey P. Dale, Sep 03 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joseph L. Pe, Sep 13 2002
EXTENSIONS
More terms from Harvey P. Dale, Sep 03 2013
STATUS
approved