%I A148071
%S A148071 1,1,2,4,9,21,51,143,374,1071,3095,8934,26170,77812,239576,719583,2245728,
               7027771,21874554,
%T A148071 68780246,217957471,699596665,2221050242,7204830752,23364983444,75490995551,
               245743450650,
%U A148071 803146080439,2641243592039,8638752159115,28638848337491,94831340109958,
               313328526209055
%N A148071 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, -1), (-1, 0, 1), 
               (0, 1, -1), (1, 0, 0)}
%H A148071 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 A148071 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, j, k, -1 + n] + aux[i, -1 + j, 
               1 + k, -1 + n] + aux[1 + i, j, -1 + k, -1 + n] + aux[1 + i, 1 + j, 
               1 + k, -1 + n]]; Table[Sum[aux[i, j, k, n], {i, 0, n}, {j, 0, n}, 
               {k, 0, n}], {n, 0, 10}]
%Y A148071 Sequence in context: A086246 A001006 A027057 this_sequence A000636 A136753 
               A084261
%Y A148071 Adjacent sequences: A148068 A148069 A148070 this_sequence A148072 A148073 
               A148074
%K A148071 nonn,walk
%O A148071 0,3
%A A148071 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008