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Search: id:A149338
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| A149338 |
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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), (-1, 0, 0), (-1, 1, 1), (0, 1, -1), (1, 0, 1)} |
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+0
1
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| 1, 1, 4, 12, 40, 149, 560, 2135, 8355, 33259, 133255, 538825, 2200026, 9034022, 37274431, 154600734, 644062873, 2692163743, 11289636850, 47490421438, 200293595870, 846706012593, 3587270304952, 15229272818359, 64770883633813, 275939465431865, 1177442622478762, 5031536426507492
(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, 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, 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}]
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CROSSREFS
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Sequence in context: A149335 A149336 A149337 this_sequence A149339 A149340 A002996
Adjacent sequences: A149335 A149336 A149337 this_sequence A149339 A149340 A149341
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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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