OFFSET
1,2
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Deficient Number
EXAMPLE
Deficient number 16 is in sequence because sigma(16) = 13 (odd number).
MATHEMATICA
aQ[n_] := OddQ[(s = DivisorSigma[1, n])] && s < 2n; Select[Range[2401], aQ] (* Amiram Eldar, Sep 02 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 22 2012
STATUS
approved