%I A150938
%S A150938 1,2,9,34,149,655,2973,13574,63259,295719,1395582,6621009,31568103,151073381,
               725686598,
%T A150938 3495808919,16883082255,81722920784,396384608135,1925902365447,9372371654353,
               45675853427404,
%U A150938 222882454310910,1088861624752285,5325182205148329,26068539172494960,127728002748159327
%N A150938 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), (0, 1, -1), 
               (0, 1, 1), (1, 0, -1), (1, 1, 1)}
%H A150938 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 A150938 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[i, -1 + j, -1 + k, -1 + n] + aux[i, 
               -1 + 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 A150938 Sequence in context: A077234 A091526 A150937 this_sequence A151307 A150939 
               A150940
%Y A150938 Adjacent sequences: A150935 A150936 A150937 this_sequence A150939 A150940 
               A150941
%K A150938 nonn,walk
%O A150938 0,2
%A A150938 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008