%I A148108
%S A148108 1,1,2,4,10,27,84,270,904,3149,11221,41052,153615,585423,2266898,8899882,
               35367261,142063183,
%T A148108 576212939,2357624559,9722575246,40382761328,168823553558,709990487405,
               3002235850977,
%U A148108 12759119302740,54477236422389,233603326611414,1005725216037108,4346070952878284
%N A148108 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, 0), 
               (0, 0, 1), (1, -1, 1), (1, 0, -1)}
%H A148108 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 A148108 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, 1 + k, -1 + n] + aux[-1 + 
               i, 1 + j, -1 + k, -1 + n] + aux[i, j, -1 + k, -1 + n] + aux[1 + i, 
               -1 + j, 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 A148108 Sequence in context: A121690 A138356 A148107 this_sequence A057786 A007776 
               A123428
%Y A148108 Adjacent sequences: A148105 A148106 A148107 this_sequence A148109 A148110 
               A148111
%K A148108 nonn,walk
%O A148108 0,3
%A A148108 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008