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Search: id:A149215
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| A149215 |
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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, 0), (-1, 1, -1), (-1, 1, 0), (1, 0, 1), (1, 1, -1)} |
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+0
1
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| 1, 1, 4, 10, 42, 136, 591, 2082, 9311, 34685, 157638, 608881, 2797083, 11084537, 51304738, 207277076, 964911964, 3957470838, 18504551737, 76820763679, 360469021179, 1511484050587, 7112923455889, 30076451061115, 141879103647396, 604235544127547, 2856174424066251, 12239406949509384
(list; graph; listen)
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OFFSET
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0,3
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LINKS
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A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted Lattice Walks, ArXiv 0811.2899.
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MATHEMATICA
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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[1 + i, -1 + j, k, -1 + n] + aux[1 + 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}]
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CROSSREFS
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Sequence in context: A114918 A149213 A149214 this_sequence A149216 A149217 A149218
Adjacent sequences: A149212 A149213 A149214 this_sequence A149216 A149217 A149218
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KEYWORD
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nonn,walk
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AUTHOR
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Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
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