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 A151150 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, -1), (0, 1, 1), (1, 0, 1), (1, 1, 0)} 0
 1, 3, 11, 47, 205, 927, 4263, 19873, 93477, 443099, 2111677, 10111271, 48593723, 234274543, 1132435961, 5486484089, 26633535227, 129513967703, 630765345243, 3076177529709, 15020545826403, 73424228430541, 359275730715121, 1759596267979597, 8625046993876771, 42310103527742087, 207699373802231315 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted Lattice Walks, ArXiv 0811.2899. MATHEMATICA 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, j, -1 + k, -1 + n] + aux[i, -1 + j, -1 + k, -1 + n] + aux[1 + i, -1 + 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}] CROSSREFS Sequence in context: A151147 A151148 A151149 * A151151 A151152 A151153 Adjacent sequences:  A151147 A151148 A151149 * A151151 A151152 A151153 KEYWORD nonn,walk AUTHOR Manuel Kauers, Nov 18 2008 STATUS approved

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