|
Search: id:A151017
|
|
|
| A151017 |
|
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, 0, 1), (0, 1, 1), (1, -1, 1), (1, 1, -1), (1, 1, 1)} |
|
+0
1
|
|
| 1, 2, 9, 39, 186, 882, 4307, 21010, 103692, 511773, 2539439, 12603464, 62722473, 312217229, 1556418854, 7760380972, 38725714681, 193279301481, 965122674081, 4819846440327, 24077535920525, 120290453853929, 601077094933615, 3003718138328801, 15012022337535169, 75031110935319189, 375039355141811408
(list; graph; listen)
|
|
|
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, -1 + j, -1 + k, -1 + n] + aux[-1 + i, -1 + j, 1 + k, -1 + n] + aux[-1 + i, 1 + j, -1 + k, -1 + n] + aux[i, -1 + j, -1 + k, -1 + n] + aux[1 + i, 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: A151014 A151015 A151016 this_sequence A151018 A096359 A020002
Adjacent sequences: A151014 A151015 A151016 this_sequence A151018 A151019 A151020
|
|
KEYWORD
|
nonn,walk
|
|
AUTHOR
|
Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
|
|
|
Search completed in 0.002 seconds
|
