|
Search: id:A151368
|
|
|
| A151368 |
|
Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, 0)} |
|
+0
1
|
|
| 1, 0, 2, 3, 12, 40, 145, 560, 2240, 9156, 38724, 166320, 728508, 3239808, 14595438, 66543477, 306511920, 1424916064, 6679435048, 31544500416, 149986398848, 717562911000, 3452381033556, 16696661334496, 81136327037620, 396022179418240, 1940898351416600, 9548613568549380, 47143311987432240
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
LINKS
|
M. Bouquet-Melou and M. Mishna, 2008. Walks with small steps in the quarter plane, ArXiv 0810.4387.
|
|
MATHEMATICA
|
aux[i_Integer, j_Integer, n_Integer] := Which[Min[i, j, n] < 0 || Max[i, j] > n, 0, n == 0, KroneckerDelta[i, j, n], True, aux[i, j, n] = aux[-1 + i, j, -1 + n] + aux[i, -1 + j, -1 + n] + aux[i, 1 + j, -1 + n] + aux[1 + i, -1 + j, -1 + n] + aux[1 + i, j, -1 + n] + aux[1 + i, 1 + j, -1 + n]]; Table[aux[0, 0, n], {n, 0, 25}]
|
|
CROSSREFS
|
Sequence in context: A012510 A012310 A082526 this_sequence A087650 A012514 A012511
Adjacent sequences: A151365 A151366 A151367 this_sequence A151369 A151370 A151371
|
|
KEYWORD
|
nonn,walk
|
|
AUTHOR
|
Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
|
|
|
Search completed in 0.002 seconds
|
