OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Deficient Number
FORMULA
a(n) < 8n/3. - Charles R Greathouse IV, Feb 19 2013
MATHEMATICA
sddn[n_]:=Module[{s=DivisorSigma[1, n]}, If[s<2n, s, 0]]; DeleteCases[ sddn/@ Range[ 100], 0] (* Harvey P. Dale, Jan 02 2015 *)
PROG
(PARI) for(n=1, 300, s=sigma(n); if(s<2*n, print1(s", "))) \\ Charles R Greathouse IV, Feb 19 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 22 2012
STATUS
approved