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 A149984 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, 0)} 0
 1, 2, 5, 17, 55, 200, 737, 2800, 10875, 42686, 170295, 683805, 2774827, 11322576, 46519469, 192043347, 796633305, 3317740288, 13867861969, 58155460455, 244585944419, 1031416896354, 4359870977953, 18470484019178, 78406877383159, 333459678106346, 1420613236435519, 6061821842982527 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS 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[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}] CROSSREFS Sequence in context: A149981 A149982 A149983 * A149985 A149986 A121193 Adjacent sequences:  A149981 A149982 A149983 * A149985 A149986 A149987 KEYWORD nonn,walk AUTHOR Manuel Kauers, Nov 18 2008 STATUS approved

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Last modified December 13 23:14 EST 2019. Contains 329974 sequences. (Running on oeis4.)