OFFSET
1,2
COMMENTS
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Range[300], IntegerQ[(#*DivisorSigma[2, #])/DivisorSigma[1, #]]&] (* Harvey P. Dale, Oct 28 2018 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Ctibor O. Zizka, Sep 25 2008
EXTENSIONS
More terms from Harvey P. Dale, Oct 28 2018
STATUS
approved