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 A339682 #4 Dec 12 2020 19:52:51
%S A339682 220,1184,469028,11693290,37784810,6057622044705,14772536572365,
%T A339682 35019687151575,19245649704560895,42564348058073842,
%U A339682 1004007953218033575,6778057036176125612
%N A339682 Lesser of amicable pair a < b such that the ratio of their number of divisors d(b)/d(a) sets a new record.
%C A339682 The larger counterparts are in A339683.
%C A339682 The corresponding ratios are 1/2, 1, 2, 3, 4, 16/3, 6, 8, 9, 12, 16, 24, ...
%C A339682 The terms were calculated using data from Chernykh's site.
%H A339682 Sergei Chernykh, <a href="http://sech.me/ap/">Amicable pairs list</a>.
%e A339682 The least pair of amicable numbers, (220, 284), has a ratio of the numbers of divisors d(284)/d(220) = 6/12 = 1/2.
%e A339682 The next pair with a larger ratio is (1184, 1210) whose ratio is d(1210)/d(1184) = 12/12 = 1.
%t A339682 s[n_] := DivisorSigma[1, n] - n; rm = 0; seq = {}; Do[m = s[n]; If[m > n && s[m] == n && (r = Divide @@ DivisorSigma[0, {m, n}]) > rm, rm = r; AppendTo[seq, n]], {n, 1, 10^7}]; seq
%Y A339682 Cf. A000005, A002025, A002046, A063990, A328255, A339683.
%K A339682 nonn,more
%O A339682 1,1
%A A339682 _Amiram Eldar_, Dec 12 2020