%I A149267
%S A149267 1,1,4,11,40,146,556,2193,8782,35996,149102,626514,2657002,11364796,49005900,
               212539829,
%T A149267 927754782,4068514036,17928721394,79325129056,352268070718,1569846519622,
               7016512277212,
%U A149267 31453931008870,141356729372092,636840991055262,2875436365711636,13009869271150484
%N A149267 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, 0, 1), 
               (0, -1, 1), (0, 0, -1), (1, 1, 0)}
%H A149267 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 A149267 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, j, 
               1 + k, -1 + n] + aux[i, 1 + j, -1 + k, -1 + n] + aux[1 + i, 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 A149267 Sequence in context: A149264 A149265 A149266 this_sequence A149268 A077236 
               A152532
%Y A149267 Adjacent sequences: A149264 A149265 A149266 this_sequence A149268 A149269 
               A149270
%K A149267 nonn,walk
%O A149267 0,3
%A A149267 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008