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 A151320 Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, 0), (0, 1), (1, -1), (1, 0), (1, 1)} 0
 1, 3, 13, 58, 270, 1280, 6150, 29805, 145360, 712206, 3501803, 17264747, 85302729, 422197260, 2092558843, 10383452493, 51573082768, 256362474771, 1275210602985, 6346900307554, 31605149836728, 157449319326981, 784667701737738, 3911759095866487, 19506630908252765, 97297440023869383 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS M. Bousquet-MÃ©lou and M. Mishna, 2008. Walks with small steps in the quarter plane, ArXiv 0810.4387. A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted Lattice Walks, ArXiv 0811.2899. 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, -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, j, -1 + n]]; Table[Sum[aux[i, j, n], {i, 0, n}, {j, 0, n}], {n, 0, 25}] CROSSREFS Sequence in context: A296771 A270786 A151226 * A151227 A151228 A268596 Adjacent sequences:  A151317 A151318 A151319 * A151321 A151322 A151323 KEYWORD nonn,walk AUTHOR Manuel Kauers, Nov 18 2008 STATUS approved

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Last modified May 27 06:28 EDT 2020. Contains 334649 sequences. (Running on oeis4.)