OFFSET
1,2
COMMENTS
Each term a(n) of this sequence is such that (2k)^2 <= a(n) < (2k+1)^2, for some nonnegative integer k.
In other words, m is not in this sequence if (2k-1)^2 <= m < (2k)^2, for any positive integer k.
LINKS
H. v. Eitzen, Table of n, a(n) for n=1..10000
MATHEMATICA
t = {a = 0}; Do[If[a < (x = DivisorSigma[0, n]), a = a + x, a = a - x]; If[a == 0, AppendTo[t, n]], {n, 1640}]; t (* Jayanta Basu, Jun 06 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Apr 21 2008
EXTENSIONS
Offset corrected ("n-th" should start with "1st", not "0th") Hagen von Eitzen, Jun 17 2009
More terms copied from b-file by Hagen von Eitzen, Jul 20 2009
STATUS
approved