OFFSET
1,1
EXAMPLE
1403+sigma(1403)+sigma(sigma(1403))=19^3.
MATHEMATICA
scQ[n_]:=Module[{c=DivisorSigma[1, n]}, IntegerQ[(n+c+DivisorSigma[1, c]) ^ (1/3)]]; Select[Range[1300000], scQ] (* Harvey P. Dale, Dec 17 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved