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 A120356 #8 Jun 13 2020 07:57:31
%S A120356 12,24,80,180,240,360,480,720,896,1344,1440,1620,2688,3240,3360,4032,
%T A120356 5040,6720,6912,8064,10080,13440,20160,20412,24300,25200,30000,30240,
%U A120356 34560,40320,40824,48600,56320,56700,60000,60480,62208,67584,69120
%N A120356 Even refactorable numbers n such that the number r of odd divisors and the number s of even divisors are both even divisors of n and n is the first number for which the triple (r,s,t) occurs, where t is the number of divisors of n.
%C A120356 Note that s is necessarily a multiple of r.
%H A120356 Amiram Eldar, <a href="/A120356/b120356.txt">Table of n, a(n) for n = 1..500</a>
%e A120356 a(1)=12 since r=2, s=4 and r+s=6.
%t A120356 triples = {}; seq = {}; Do[t = DivisorSigma[0, n]; r = DivisorSigma[0, 2 n] - t; s = t - r; tri = {r, s, t}; If[AllTrue[tri, EvenQ[#] && Divisible[n, #] &] && !MemberQ[triples, tri], AppendTo[seq, n]; AppendTo[triples, tri]], {n, 2, 69120, 2}]; seq (* _Amiram Eldar_, Jun 13 2020 *)
%Y A120356 Cf. A001227, A033950, A049439, A057265, A183063.
%K A120356 nonn
%O A120356 1,1
%A A120356 _Walter Kehowski_, Jun 25 2006