|
Search: id:A149250
|
|
|
| A149250 |
|
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), (-1, 1, 1), (0, 0, -1), (1, 0, 1)} |
|
+0
1
|
|
| 1, 1, 4, 11, 38, 127, 469, 1705, 6434, 24389, 94673, 368739, 1454964, 5771801, 23119934, 92992567, 376491106, 1530495385, 6254576881, 25645425145, 105575282808, 435948047107, 1806201329260, 7502709964453, 31250854106498, 130469673686333, 545989888478305, 2289461874839921, 9619648511288570
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
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, -1 + k, -1 + n] + aux[i, j, 1 + k, -1 + n] + aux[1 + i, -1 + 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}]
|
|
CROSSREFS
|
Sequence in context: A149247 A149248 A149249 this_sequence A149251 A149252 A149253
Adjacent sequences: A149247 A149248 A149249 this_sequence A149251 A149252 A149253
|
|
KEYWORD
|
nonn,walk
|
|
AUTHOR
|
Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
|
|
|
Search completed in 0.002 seconds
|
