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A149833
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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), (0, 0, -1), (0, 1, -1), (0, 1, 0), (1, 0, 0)}
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0
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1, 2, 4, 10, 30, 94, 309, 1068, 3798, 13854, 51834, 197150, 761151, 2984766, 11841509, 47428821, 191899909, 783286480, 3219622765, 13325287138, 55516004988, 232584392264, 979365099918, 4144435559953, 17617616589605, 75193307662253, 322164970730139, 1385350445979640, 5977051004543671
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted Lattice Walks, ArXiv 0811.2899.
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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, j, k, -1 + n] + aux[i, -1 + j, k, -1 + n] + aux[i, -1 + j, 1 + k, -1 + n] + aux[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}]
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CROSSREFS
| Sequence in context: A102667 A148115 A148116 * A026119 A149834 A149835
Adjacent sequences: A149830 A149831 A149832 * A149834 A149835 A149836
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KEYWORD
| nonn,walk
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AUTHOR
| Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
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