OFFSET
1,1
EXAMPLE
16 is in the list since 16 = 4^2 and sigma(16)+d(16) = 36 = 6^2. Also 278784 = 528^2 and sigma(278784)+d(278784) = 883600 = 940^2.
MATHEMATICA
Sqd[n_] := Sqrt[DivisorSigma[1, n] + DivisorSigma[0, n]]; t = {}; Do[If[IntegerQ[Sqd[n^2]], AppendTo[t, n^2]], {n, 1500000}]; t
CROSSREFS
KEYWORD
nonn
AUTHOR
Jayanta Basu, Apr 10 2013
EXTENSIONS
a(11)-a(19) from Donovan Johnson, Apr 10 2013
STATUS
approved