%I A019472
%S A019472 0,0,1,7,51,421,3963,42253,505515,6724381,98618763,1582715773,27612565995,
%T A019472 520631327581,10554164679243,228975516609853,5294731892093355,130015079601039901,
%U A019472 3379132289551117323,92679942218919579133,2675254894236207563115
%N A019472 Weak preference orderings of n alternatives, i.e. orderings that have 
               indifference between at least two alternatives.
%F A019472 A000670(n) - n!.
%Y A019472 Sequence in context: A162757 A147958 A104454 this_sequence A081216 A124271 
               A156751
%Y A019472 Adjacent sequences: A019469 A019470 A019471 this_sequence A019473 A019474 
               A019475
%K A019472 nonn,easy,nice
%O A019472 0,4
%A A019472 Robert Ware (bware(AT)wam.umd.edu)
%E A019472 Formula corrected by Eugene McDonnell, May 12, 2000