%I A149303
%S A149303 1,1,4,11,46,174,740,3109,13614,59878,268728,1214032,5546558,25498422,
               118054700,549367029,
%T A149303 2569472992,12066493332,56883907318,269035738044,1276275732442,6070582701920,
               28945492531456,
%U A149303 138319277521604,662316708110916,3177211680848070,15267484859916084,73479492803233664
%N A149303 Number of walks within N^3 (the first octant of Z^3) starting at (0,0,
               0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, 1), 
               (0, 0, -1), (1, -1, 1), (1, 1, 0)}
%H A149303 A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted 
               Lattice Walks, <a href="http://arxiv.org/abs/0811.2899">ArXiv 0811.2899</
               a>.
%t A149303 aux[i_Integer, j_Integer, k_Integer, n_Integer] := Which[Min[i, j, k, 
               n] < 0 || Max[i, j, k] > n, 0, n == 0, KroneckerDelta[i, j, k, n], 
               True, aux[i, j, k, n] = aux[-1 + i, -1 + j, k, -1 + n] + aux[-1 + 
               i, 1 + j, -1 + k, -1 + n] + aux[i, j, 1 + k, -1 + n] + aux[1 + i, 
               -1 + j, -1 + k, -1 + n] + aux[1 + i, 1 + j, k, -1 + n]]; Table[Sum[aux[i, 
               j, k, n], {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 10}]
%Y A149303 Sequence in context: A149300 A149301 A149302 this_sequence A053882 A149304 
               A149305
%Y A149303 Adjacent sequences: A149300 A149301 A149302 this_sequence A149304 A149305 
               A149306
%K A149303 nonn,walk
%O A149303 0,3
%A A149303 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008