%I A060638
%S A060638 0,1,0,4,1,0,12,6,1,0,32,36,8,1,0,80,240,100,10,1,0,192,1800,2144,
%T A060638 264,12,1,0,448,15120,80360,22624,672,14,1,0,1024,141120
%N A060638 Triangle T(n,k) (0 <= k <= n) giving number of edges in the "flip graph" 
               whose nodes are the tilings of the unary zonotope Z(n,k) (the projection 
               onto R^k of a unit cube in R^n) by projections of the k-dimensional 
               faces of the hypercube (again projected onto R^k).
%D A060638 A. Bjorner, M. Las Vergnas, B. Sturmfels, N. White and G. M. Ziegler, 
               Oriented Matroids, Encyclopedia of Mathematics 46, Second Edition, 
               Cambridge University Press, 1999
%D A060638 N. Destainville, R. Mosseri and F. Bailly, Fixed-boundary octagonal random 
               tilings: a combinatorial approach, Journal of Statistical Physics, 
               102 (2001), no. 1-2, 147-190.
%D A060638 Victor Reiner, The generalized Baues problem, in New Perspectives in 
               Algebraic Combinatorics (Berkeley, CA, 1996-1997), 293-336, Math. 
               Sci. Res. Inst. Publ., 38, Cambridge Univ. Press, Cambridge, 1999.
%H A060638 M. Latapy, <a href="http://www.liafa.jussieu.fr/~latapy/Zono/index.html">
               Tilings of zonotopes</a>
%e A060638 0; 1,0; 4,1,0; 12,6,1,0; ...
%Y A060638 Diagonals give A001787, A001286, A060570, A060608, A060612, A060614, 
               A060616-A060619, A060621-A060624. Cf. A060637.
%Y A060638 Sequence in context: A127155 A145880 A048516 this_sequence A007789 A081114 
               A069018
%Y A060638 Adjacent sequences: A060635 A060636 A060637 this_sequence A060639 A060640 
               A060641
%K A060638 nonn,tabl,hard,nice
%O A060638 0,4
%A A060638 N. J. A. Sloane (njas(AT)research.att.com), Apr 16 2001