%I A056937
%S A056937 1,980,211250,17792748,781429368,21238316210,398925639186,
%T A056937 5585711269074,61555624183223,555895303974238,4242859829536322,
%U A056937 28038281717424550,163544036697306396,855242362045150398
%N A056937 Number of antichains (or order ideals) in the poset 3*3*3*n or size of 
               the distributive lattice J(3*3*3*n)
%D A056937 Berman and Koehler, Cardinalities of finite distributive lattices, Mitteilungen 
               aus dem Mathematischen Seminar Giessen, 121 (1976), p. 103-124
%H A056937 <a href="Sindx_Pos.html#posets">Index entries for sequences related to 
               posets</a>
%t A056937 MatrixPower[ ZetaP[ #, n + 1 ][ [ 1, Card[ # ] ] ]&@JofP[ Chain[ 3, 3, 
               3 ] ]
%Y A056937 Cf. A000372, A006360, A006361, A006362, A056932, A056933, A056934, A056935, 
               A056936.
%Y A056937 Sequence in context: A157515 A109120 A128483 this_sequence A122472 A087907 
               A096701
%Y A056937 Adjacent sequences: A056934 A056935 A056936 this_sequence A056938 A056939 
               A056940
%K A056937 nonn,easy
%O A056937 0,2
%A A056937 Mitch Harris (Harris.Mitchell(AT)mgh.harvard.edu)