%I A148162
%S A148162 1,1,2,4,11,31,91,267,813,2557,8236,26786,87847,291227,977068,3308866,
               11278661,38653717,
%T A148162 133227658,461825572,1608935543,5628584683,19762998641,69637415101,246214217449,
               873256171561,
%U A148162 3105884952236,11074941003322,39586724293339,141826521919151,509214076570561,
               1831934157570821
%N A148162 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, 0, -1), (1, 0, 0)}
%H A148162 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 A148162 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, j, 1 + 
               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 A148162 Sequence in context: A002387 A148160 A148161 this_sequence A148163 A039300 
               A118974
%Y A148162 Adjacent sequences: A148159 A148160 A148161 this_sequence A148163 A148164 
               A148165
%K A148162 nonn,walk
%O A148162 0,3
%A A148162 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008