OFFSET
1,1
MATHEMATICA
F[n_] := Abs[EulerPhi[n] - n]; Q[n_] := n+F[n]+F[n-F[n]]; Do[If[Q[n] == DivisorSigma[1, n] - n, Print[n]], {n, 10^9}] (* Ryan Propper, Jan 01 2007 *)
PROG
(PARI) e(n) = n - eulerphi(n);
q(n) = n+e(n)+e(n-e(n));
for(n=1, 10^8, if(q(n)==sigma(n)-n, print1(n, ", ")))
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Jason Earls, Aug 31 2001
EXTENSIONS
One more term from Ryan Propper, Jan 01 2007
a(10)-a(12) from Lars Blomberg, Oct 27 2015
Offset corrected by Altug Alkan, Oct 31 2015
STATUS
approved