%I A150026
%S A150026 1,2,5,19,74,272,1128,4785,19680,85534,375994,1621412,7228110,32438712,
               143597689,649971056,
%T A150026 2955472000,13301538596,60825607272,279067019064,1270235883915,5851260862078,
               27020828578132,
%U A150026 123996284280459,574325273769182,2665349207045963,12306252890649850,57243664510934520
%N A150026 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, -1, 0), (-1, -1, 1), 
               (0, 1, -1), (0, 1, 0), (1, 0, 1)}
%H A150026 A. Bostan and M. Kauers, 2008. Automatic Classification of Restricted 
               Lattice Walks, <a href="http://arxiv.org/abs/0811.2899">ArXiv 0811.2899</
               a>.
%t A150026 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, j, -1 + k, -1 + n] + aux[i, -1 
               + j, k, -1 + n] + aux[i, -1 + j, 1 + k, -1 + n] + aux[1 + i, 1 + 
               j, -1 + k, -1 + n] + aux[1 + i, 1 + j, k, -1 + n]]; Table[Sum[aux[i, 
               j, k, n], {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 10}]
%Y A150026 Sequence in context: A148437 A106873 A014273 this_sequence A150027 A058131 
               A138911
%Y A150026 Adjacent sequences: A150023 A150024 A150025 this_sequence A150027 A150028 
               A150029
%K A150026 nonn,walk
%O A150026 0,2
%A A150026 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008