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 A090126 #12 May 27 2020 11:54:33
%S A090126 6,30,42,66,2730,510,798,330,138,870,14322,1919190,13530,1806,690,282,
%T A090126 46410,1590,354,56786730,64722,4686,140100870,3318,230010,498,3404310,
%U A090126 61410,272118,1410,4501770,33330,4326,642,209191710,1518,1671270,1770
%N A090126 Distinct values of denominators of Bernoulli numbers B(2n) in order of their appearance as n grows.
%H A090126 R. J. Mathar, <a href="/A090126/b090126.txt">Table of n, a(n) for n = 1..842</a>
%t A090126 t=Table[Denominator[BernoulliB[2*w]], {w, 1, 100}] s=Sort[t];u=Union[t];Length[u] Table[Count[s, Part[u, j]], {j, 1, Length[u]}] g=Table[Min[Flatten[Position[t, Part[u, j]]]], {j, 1, Length[u]}]; uu=Union[g];Table[Part[t, Part[uu, j]], {j, 1, Length[g]}]
%t A090126 t = Table[Denominator[BernoulliB[n]], {n, 2, 3000, 2}]; For[n = 1, n <= Length[t], n++, p = Position[t, t[[n]]] // Rest; t = Delete[t, p]]; t (* _Jean-François Alcover_, Oct 14 2014 *)
%t A090126 DeleteDuplicates[Denominator[BernoulliB[2*Range[100]]]] (* _Harvey P. Dale_, May 27 2020 *)
%Y A090126 Cf. A027641, A027642.
%K A090126 nonn
%O A090126 1,1
%A A090126 _Labos Elemer_, Jan 16 2004