%I A149118
%S A149118 1,1,4,9,32,103,345,1275,4410,16741,61731,233495,902378,3437487,13553036,
52676569,208717276,
%T A149118 828362597,3294044819,13255061489,53113955276,215179562527,870783523200,
3541185265429,
%U A149118 14454981038936,59025273287545,242367745510571,994814873513383,4100366928340036
%N A149118 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),
(-1, 0, 0), (0, -1, 1), (1, 1, 0)}
%H A149118 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 A149118 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[1 + i, j, 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 A149118 Sequence in context: A149115 A149116 A149117 this_sequence A149119 A149120
A057819
%Y A149118 Adjacent sequences: A149115 A149116 A149117 this_sequence A149119 A149120
A149121
%K A149118 nonn,walk
%O A149118 0,3
%A A149118 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
|