This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A181487 #13 Jan 06 2024 19:00:50
%S A181487 12,18,20,30,42,48,56,66,70,72,78,80,84,88,90,102,104,108,114,120,138,
%T A181487 150,162,174,180,186,192,196,200,210,220,222,246,252,258,260,264,270,
%U A181487 272,280,282,288,294,300,304,308,312,318,320,330,336,340,354,364,366
%N A181487 Numbers k such that Sum_{d|k, d<k, d not occurring before} d > k.
%C A181487 This is the complement of the set S occurring in S-perfect numbers A118372.
%C A181487 From _Amiram Eldar_, Aug 11 2023: (Start)
%C A181487 Sometimes called S-abundant numbers, since they are analogous to abundant numbers (A005101) as S-perfect numbers (A118372) are analogous to perfect numbers (A000396).
%C A181487 De Koninck and Ivić conjectured that this sequence has an asymptotic density.
%C A181487 The numbers of terms not exceeding 10^k, for k = 2, 3, ..., are 15, 152, 1567, 15336, 154301, 1541445, 15392073, ... . Apparently, the asymptotic density of this sequence exists and equals 0.15... . (End)
%D A181487 Elena Deza, Perfect and Amicable Numbers, World Scientific, 2023, pp. 325-327.
%H A181487 Donovan Johnson, <a href="/A181487/b181487.txt">Table of n, a(n) for n = 1..10000</a>
%H A181487 Jean-Marie De Koninck and Aleksandar Ivić, <a href="https://www.emis.de/journals/PIMB/078/2.html">On a sum of divisors problem</a>, Publications de l'Institut Mathématique (Beograd), New Series, Vol. 64 (78) (1998), pp. 9-20.
%H A181487 Gérard Villemin, <a href="http://villemin.gerard.free.fr/aNombre/TYPDIVIS/ParfaitS.htm">Nombres S-PARFAITS ou Nombres de Granville</a>, NOMBRES - Curiosités, théorie et usages, 2019 (in French).
%H A181487 Wikipedia, <a href="https://en.wikipedia.org/wiki/Granville_number">Granville number</a>.
%t A181487 seq[kmax_] := Module[{s = {1}, a = {}, sum}, Do[sum = Total[Select[Divisors[k], MemberQ[s, #] &]]; If[sum <= k, AppendTo[s, k], AppendTo[a, k]], {k, 2, kmax}]; a]; seq[400] (* _Amiram Eldar_, Aug 11 2023 *)
%o A181487 (PARI) A181487(Nmax) = { my(C=0); for(n=2,Nmax, sumdiv(n,d,!bittest(C,d)*d)>2*n & !print1(n", ") & C+=1<<n )}
%Y A181487 Cf. A000396, A005101, A118372.
%K A181487 nonn
%O A181487 1,1
%A A181487 _M. F. Hasler_, Oct 28 2010