OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1)=4 because the first admirable number is 12 and sigma(12)-24 = 4.
MATHEMATICA
fn[n_]:=DivisorSigma[1, n]-2*n; fn/@Select[Range[1155], MemberQ[Most[Divisors[#]], (DivisorSigma[1, #]-2*#)/2]&] (* James C. McMahon, Jun 02 2024 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jason Earls, Aug 14 2005
STATUS
approved