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 A333929 #8 Apr 12 2020 09:50:09
%S A333929 220,366,2620,3864,5020,16104,16536,26448,29760,43524,63020,67344,
%T A333929 69615,100485,122265,142290,142310,196248,196724,198990,239856,240312,
%U A333929 280540,308620,309264,319550,326424,341904,348840,366792,469028,522405,537744,580320,647190,661776
%N A333929 Lesser of recursive amicable numbers pair: numbers m < k such that m = s(k) and k = s(m), where s(k) = A333926(k) - k is the sum of proper recursive divisors of k.
%C A333929 The larger counterparts are in A333930.
%H A333929 Amiram Eldar, <a href="/A333929/b333929.txt">Table of n, a(n) for n = 1..1000</a>
%e A333929 220 is a terms since A333926(220) - 220 = 284 and A333926(284) - 284 = 220.
%t A333929 recDivQ[n_, 1] = True; recDivQ[n_, d_] := recDivQ[n, d] = Divisible[n, d] && AllTrue[FactorInteger[d], recDivQ[IntegerExponent[n, First[#]], Last[#]] &]; recDivs[n_] := Select[Divisors[n], recDivQ[n, #] &]; f[p_, e_] := 1 + Total[p^recDivs[e]]; recDivSum[1] = 1; recDivSum[n_] := Times @@ (f @@@ FactorInteger[n]); s[n_] := recDivSum[n] - n; seq = {}; Do[m = s[n]; If[m > n && s[m] == n, AppendTo[seq, n]], {n, 1, 10^5}]; seq
%Y A333929 Cf. A333926, A333927, A333930.
%Y A333929 Analogous sequences: A002025, A002952 (unitary), A126165 (exponential), A126169 (infinitary), A292980 (bi-unitary).
%K A333929 nonn
%O A333929 1,1
%A A333929 _Amiram Eldar_, Apr 10 2020