OFFSET
1,1
COMMENTS
REFERENCES
Melvyn B. Nathanson, Elementary Methods in Number Theory, Springer, 2000, p 260.
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
Richard Laatsch, Measuring the Abundancy of Integers, Mathematics Magazine, Vol. 59, No. 2 (1986), pp. 84-92, alternative link.
FORMULA
A001221(a(n)) >= 3 (Laatsch, 1986). - Amiram Eldar, Nov 07 2020
MAPLE
select(t -> numtheory:-sigma(t) >= 3*t, [$1..10000]); # Robert Israel, Dec 28 2014
MATHEMATICA
Select[Range[10000], DivisorSigma[1, #] >= 3*#&] (* Vladimir Joseph Stephan Orlovsky, Apr 21 2010 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved