OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000 (terms 1..500 from Donovan Johnson)
FORMULA
MATHEMATICA
Select[Sqrt[DivisorSigma[2, #]] & /@ Range[750000], IntegerQ] (* Jayanta Basu, Jun 27 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved