%I A148996
%S A148996 1,1,3,9,33,119,454,1779,7152,29311,122013,514390,2192976,9435593,40927132,
               178767188,785677788,
%T A148996 3471969333,15417894851,68766083151,307921250078,1383758689713,6238746051177,
               28211698413079,
%U A148996 127923279261484,581519329356110,2649655569254817,12099042388429222,55358244255747829
%N A148996 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, 0, 0), (0, -1, 1), 
               (1, -1, 1), (1, 0, 1), (1, 1, -1)}
%H A148996 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 A148996 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, 1 + k, -1 + n] + aux[-1 
               + i, j, -1 + k, -1 + n] + aux[-1 + i, 1 + j, -1 + k, -1 + n] + aux[i, 
               1 + j, -1 + k, -1 + n] + aux[1 + i, j, k, -1 + n]]; Table[Sum[aux[i, 
               j, k, n], {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 10}]
%Y A148996 Sequence in context: A148993 A148994 A148995 this_sequence A148997 A082841 
               A151038
%Y A148996 Adjacent sequences: A148993 A148994 A148995 this_sequence A148997 A148998 
               A148999
%K A148996 nonn,walk
%O A148996 0,3
%A A148996 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008