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 A300664 #13 Sep 17 2019 16:54:14
%S A300664 120,840,1080,1320,1512,1560,1848,1890,1920,2040,2184,2280,2376,2688,
%T A300664 2760,2856,3000,3192,3480,3720,4440,4920,5160,5640,5880,6360,7080,
%U A300664 7320,7560,8040,8520,8760,9240,9480,9720,9960,10680,10920,11640,11880,12120,12360
%N A300664 Infinitary 3-abundant numbers: numbers n such that isigma(n) >= 3n, where isigma is the sum of infinitary divisors of n (A049417).
%C A300664 Analogous to 3-abundant numbers (A023197) with isigma (A049417) instead of sigma (A000203).
%H A300664 Amiram Eldar, <a href="/A300664/b300664.txt">Table of n, a(n) for n = 1..10000</a>
%e A300664 840 is in the sequence since isigma(840) = 2880 > 3 * 840.
%t A300664 ExponentList[n_Integer, factors_List] := {#, IntegerExponent[n, #]} & /@ factors; InfinitaryDivisors[1] := {1}; InfinitaryDivisors[n_Integer ? Positive] := Module[{factors = First /@ FactorInteger[n], d = Divisors[n]}, d[[Flatten[ Position[ Transpose[ Thread[Function[{f, g}, BitOr[f, g] == g][#, Last[#]]] & /@ Transpose[ Last /@ ExponentList[#, factors] & /@ d]], _?(And @@ # &), {1}]]]]]; properinfinitarydivisorsum[k_] := Plus @@ InfinitaryDivisors[k] - k; Infinitary3AbundantNumberQ[k_] := If[properinfinitarydivisorsum[k] >= 2 k, True, False]; Select[Range[15000], Infinitary3AbundantNumberQ[#] &] (* after _Ant King_ at A129656 *)
%Y A300664 Cf. A007357, A023197, A049417, A129656, A129657.
%K A300664 nonn
%O A300664 1,1
%A A300664 _Amiram Eldar_, Mar 10 2018