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 A265712 #18 Sep 08 2022 08:46:15
%S A265712 60,72,84,90,120,144,168,180,210,216,240,252,264,270,280,288,300,312,
%T A265712 324,330,336,360,378,384,390,396,408,420,432,450,456,462,468,480,504,
%U A265712 510,528,540,546,552,560,570,576,588,600,612,624,630,648,660,672,684,690
%N A265712 Numbers n such that floor(Sum_{d|n} 1 / sigma(d)) = 2.
%C A265712 Numbers n such that A265710(n) = floor(A265708(n) / A069934(n)) = floor(A265709(n) / A265710(n)) = 2.
%C A265712 See A265714(n) = the smallest number k such that floor(Sum_{d|k} 1/sigma(d)) = n.
%H A265712 G. C. Greubel, <a href="/A265712/b265712.txt">Table of n, a(n) for n = 1..7334</a>
%e A265712 60 is a term because floor(Sum_{d|60} 1/sigma(d)) = floor(155/72) = 2.
%t A265712 Select[Range@ 690, Floor[Sum[1/DivisorSigma[1, d], {d, Divisors@ #}]] == 2 &] (* _Michael De Vlieger_, Dec 31 2015 *)
%o A265712 (Magma) [n: n in [1..1000] | Floor(&+[1/SumOfDivisors(d): d in Divisors(n)]) eq 2]
%o A265712 (PARI) isok(n) = floor(sumdiv(n, d, 1/sigma(d))) == 2; \\ _Michel Marcus_, Dec 27 2015
%Y A265712 Cf. A069934, A000203, A265708, A265709, A265710, A265711, A265713, A265714, A266227, A266228.
%K A265712 nonn
%O A265712 1,1
%A A265712 _Jaroslav Krizek_, Dec 25 2015