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 A004122 M2064 #20 Jan 31 2022 01:28:11
%S A004122 2,13,123,1546,24283,457699,10064848,252945467,7151532895,
%T A004122 224661610888,7763387794649,292659248485051,11951855446598278,
%U A004122 525645673381008537,24769319755329986599,1244984053628241578058,66487872534167725541751
%N A004122 Generalized weak orders on n points.
%D A004122 I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, John Wiley and Sons, N.Y., 1983.
%D A004122 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%D A004122 C. G. Wagner, Enumeration of generalized weak orders. Arch. Math. (Basel) 39 (1982), no. 2, 147-152.
%H A004122 T. D. Noe, <a href="/A004122/b004122.txt">Table of n, a(n) for n = 1..100</a>
%H A004122 C. G. Wagner, <a href="/A004121/a004121_1.pdf">Enumeration of generalized weak orders</a>, Preprint, 1980. [Annotated scanned copy]
%H A004122 C. G. Wagner and N. J. A. Sloane, <a href="/A004121/a004121.pdf">Correspondence, 1980</a>
%F A004122 E.g.f. : 1/(2-exp(x)*exp(exp(x)-1)).
%t A004122 With[{nn=20},Rest[CoefficientList[Series[1/(2-Exp[x]Exp[Exp[x]-1]),{x,0,nn}], x] Range[0,nn]!]] (* _Harvey P. Dale_, Nov 05 2011 *)
%Y A004122 Cf. A004121, A004123, A000670.
%K A004122 nonn,nice,easy
%O A004122 1,1
%A A004122 _N. J. A. Sloane_
%E A004122 Formula and more terms from _Vladeta Jovovic_, Mar 27 2001