%I A149248
%S A149248 1,1,4,11,38,127,469,1677,6378,24095,93609,362445,1436332,5676421,22781348,
               91416871,370922058,
%T A149248 1504651077,6159395169,25221691069,103977918900,428932959075,1779227261594,
               7385144690729,
%U A149248 30792699917314,128496500238255,538174185677349,2255895860083435,9485551742409292
%N A149248 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, 0), 
               (1, -1, 0), (1, -1, 1), (1, 1, 0)}
%H A149248 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 A149248 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[-1 + 
               i, 1 + j, -1 + k, -1 + n] + aux[-1 + i, 1 + j, k, -1 + n] + aux[1 
               + i, 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 A149248 Sequence in context: A027573 A149246 A149247 this_sequence A149249 A149250 
               A149251
%Y A149248 Adjacent sequences: A149245 A149246 A149247 this_sequence A149249 A149250 
               A149251
%K A149248 nonn,walk
%O A149248 0,3
%A A149248 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008