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A148338 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, 0, -1), (0, 1, -1), (1, 0, 0)} 0
1, 1, 2, 5, 14, 47, 163, 557, 2032, 7620, 28483, 110339, 435718, 1715808, 6908927, 28168216, 114527372, 473085369, 1972380056, 8202101812, 34515070572, 146288036328, 618565633708, 2639880886657, 11331006947773, 48530304463065, 209417051716828, 907923273082390, 3928407904401407 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..28.

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, 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] + 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: A149901 A149902 A047026 * A149903 A149904 A287888

Adjacent sequences:  A148335 A148336 A148337 * A148339 A148340 A148341

KEYWORD

nonn,walk

AUTHOR

Manuel Kauers, Nov 18 2008

STATUS

approved

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Last modified July 5 08:40 EDT 2022. Contains 355093 sequences. (Running on oeis4.)