OFFSET
1,1
EXAMPLE
914 + sigma(914) + phi(914) = 14^3.
MATHEMATICA
Select[Range[300000], IntegerQ[Surd[#+DivisorSigma[1, #]+EulerPhi[#], 3]]&] (* Harvey P. Dale, May 02 2019 *)
PROG
(PARI) isok(n) = ispower (n + sigma(n) + eulerphi(n), 3); \\ Michel Marcus, Jan 26 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved