%I A148874
%S A148874 1,1,3,8,29,97,356,1345,5312,20951,84910,349614,1456834,6106706,25935852,
               111040569,477930029,
%T A148874 2069560858,9025183157,39530097395,173797714040,767680927436,3404799777699,
               15144014386727,
%U A148874 67566885275210,302450951239750,1357363670407487,6105291074781927,27528978458057805
%N A148874 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, 0, 1), 
               (0, 1, -1), (0, 1, 1), (1, -1, 0)}
%H A148874 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 A148874 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, -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, -1 + k, -1 + n]]; Table[Sum[aux[i, 
               j, k, n], {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 10}]
%Y A148874 Sequence in context: A148871 A148872 A148873 this_sequence A022017 A148875 
               A148876
%Y A148874 Adjacent sequences: A148871 A148872 A148873 this_sequence A148875 A148876 
               A148877
%K A148874 nonn,walk
%O A148874 0,3
%A A148874 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008