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 A206030 #17 Sep 27 2024 17:07:55
%S A206030 66,132,170,198,210,260,264,322,330,340,345,396,400,420,456,462,510,
%T A206030 520,528,594,630,644,651,660,680,690,726,780,792,800,820,840,850,858,
%U A206030 912,924,966,990,1020,1035,1040,1050,1056,1066,1092,1122,1155,1160,1188
%N A206030 Numbers m with at least two divisors d with the same sigma(d).
%C A206030 Complement of sequence contains numbers whose divisors d have distinct values of sigma(d).
%H A206030 Andrew Howroyd, <a href="/A206030/b206030.txt">Table of n, a(n) for n = 1..10000</a>
%e A206030 66 is in sequence because two divisors d (6 and 11) of 66 have the same sigma(d) = 12.
%t A206030 Select[Range[1200], Length[DivisorSigma[1, Divisors[#]]] != Length[Union[DivisorSigma[1, Divisors[#]]]] &] (* _T. D. Noe_, Feb 10 2012 *)
%t A206030 [Range[1200],Max[Tally[DivisorSigma[1,Divisors[#]]][[;;,2]]]>1&] (* _Harvey P. Dale_, Sep 27 2024 *)
%o A206030 (PARI) ok(n)={my(v=apply(sigma, divisors(n))); #Set(v) < #v} \\ _Andrew Howroyd_, Aug 01 2018
%Y A206030 Cf. A000203, A007609, A085790.
%K A206030 nonn
%O A206030 1,1
%A A206030 _Jaroslav Krizek_, Feb 03 2012