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 A307820 #11 Sep 09 2022 03:50:47
%S A307820 0,12,114,1270,12518,125634,1257749,12570993,125716733,1256921422,
%T A307820 12570417639
%N A307820 The number of infinitary abundant numbers below 10^n.
%F A307820 Conjecture: Lim_{n->oo} a(n)/10^n = 0.125... is the density of infinitary abundant numbers.
%e A307820 Below 10^2 there are 12 infinitary abundant numbers, 24, 30, 40, 42, 54, 56, 66, 70, 72, 78, 88, and 96, thus a(2) = 12.
%t A307820 fun[p_, e_] := Module[{ b = IntegerDigits[e, 2]}, m=Length[b]; Product[If[b[[j]] > 0, 1+p^(2^(m-j)), 1], {j, 1, m}]]; isigma[1]=1; isigma[n_] := Times @@ fun @@@ FactorInteger[n]; c = 0; k = 1; seq={}; Do[ While[ k < 10^n, If[ isigma[k]>2k, c++ ]; k ++]; AppendTo[seq, c], {n, 1, 5}]; seq
%Y A307820 Cf. A049417, A129656, A302992, A302993, A302994, A307821, A307823.
%K A307820 nonn,more
%O A307820 1,2
%A A307820 _Amiram Eldar_, Apr 30 2019
%E A307820 a(11) from _Amiram Eldar_, Sep 09 2022