%I A149854
%S A149854 1,2,5,13,37,111,346,1100,3557,11683,38926,131154,445765,1526305,5261985,
               18254431,63672445,
%T A149854 223138635,785267758,2774187398,9835528373,34983477901,124795716145,446376963933,
               1600610895841,
%U A149854 5752771831361,20720666878796,74782199279800,270397125942817,979410568546113,
               3553373294757136
%N A149854 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, -1, 1), 
               (0, 1, 0), (1, 1, 0)}
%H A149854 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 A149854 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[i, -1 
               + j, k, -1 + n] + aux[1 + i, 1 + 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 A149854 Sequence in context: A151416 A114509 A003080 this_sequence A151442 A053732 
               A119495
%Y A149854 Adjacent sequences: A149851 A149852 A149853 this_sequence A149855 A149856 
               A149857
%K A149854 nonn,walk
%O A149854 0,2
%A A149854 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008