Search: id:A151445 Results 1-1 of 1 results found. %I A151445 %S A151445 1,1,2,6,16,49,165,538,1881,6673,23954,87931,326739,1224662,4649697,17778696, 68513483, %T A151445 265907818,1038089219,4074688736,16076107171,63703583554,253492204031, 1012528480799, %U A151445 4058431546038,16319598817463,65820404923113,266202737052052,1079421216584541, 4387508855164279 %N A151445 Number of walks within N^2 (the first quadrant of Z^2) starting at (0, 0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (0, 1), (1, -1), (1, 0), (1, 1)} %H A151445 M. Bouquet-Melou and M. Mishna, 2008. Walks with small steps in the quarter plane, ArXiv 0810.4387. %t A151445 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, -1 + j, -1 + n] + aux[-1 + i, j, -1 + n] + aux[-1 + i, 1 + j, -1 + n] + aux[i, -1 + j, -1 + n] + aux[1 + i, 1 + j, -1 + n]]; Table[Sum[aux[0, k, n], {k, 0, n}], {n, 0, 25}] %Y A151445 Sequence in context: A079565 A052890 A052814 this_sequence A000136 A013989 A002841 %Y A151445 Adjacent sequences: A151442 A151443 A151444 this_sequence A151446 A151447 A151448 %K A151445 nonn,walk %O A151445 0,3 %A A151445 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008 Search completed in 0.001 seconds