|
Search: id:A151348
|
|
|
| A151348 |
|
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), (1, 0)} |
|
+0
1
|
|
| 1, 0, 1, 1, 4, 7, 25, 64, 201, 612, 1961, 6355, 21026, 70968, 241810, 837191, 2925393, 10334302, 36813216, 132242756, 478470272, 1742816732, 6387201912, 23539830561, 87207544029, 324627673245, 1213820275167, 4557447698656, 17177881979810, 64981216839823, 246648317043660, 939184339480746, 3586940782960596
(list; graph; listen)
|
|
|
OFFSET
|
0,5
|
|
|
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[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: A079441 A129418 A073218 this_sequence A110413 A075686 A077441
Adjacent sequences: A151345 A151346 A151347 this_sequence A151349 A151350 A151351
|
|
KEYWORD
|
nonn,walk
|
|
AUTHOR
|
Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008
|
|
|
Search completed in 0.002 seconds
|
