%I A004122 M2064
%S A004122 2,13,123,1546,24283,457699,10064848,252945467,7151532895,224661610888,
%T A004122 7763387794649,292659248485051,11951855446598278,525645673381008537,
%U A004122 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="b004122.txt">Table of n, a(n) for n=1..100</a>
%F A004122 E.g.f. : 1/(2-exp(x)*exp(exp(x)-1)).
%Y A004122 Cf. A004121, A004123, A000670.
%Y A004122 Sequence in context: A127891 A110369 A000180 this_sequence A086630 A151361 
               A073559
%Y A004122 Adjacent sequences: A004119 A004120 A004121 this_sequence A004123 A004124 
               A004125
%K A004122 nonn,nice,easy
%O A004122 1,1
%A A004122 N. J. A. Sloane (njas(AT)research.att.com).
%E A004122 Formula and more terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 
               27 2001