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Search: id:A150569
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| A150569 |
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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, 1), (0, 0, 1), (1, 0, 1), (1, 1, -1)} |
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+0
1
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| 1, 2, 7, 26, 108, 452, 1994, 8845, 40271, 184235, 855223, 3985965, 18744281, 88440574, 419747961, 1997680208, 9546471924, 45725577789, 219672576950, 1057375409941, 5101190127636, 24650121338944, 119328509102064, 578453160526799, 2808152514137111, 13648520420291810, 66415602018946462
(list; graph; listen)
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OFFSET
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0,2
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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[i, j, -1 + k, -1 + n] + aux[1 + 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
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Sequence in context: A080244 A124542 A003447 this_sequence A150570 A150571 A150572
Adjacent sequences: A150566 A150567 A150568 this_sequence A150570 A150571 A150572
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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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