%I A151019
%S A151019 1,2,10,32,160,584,2920,11360,56800,229568,1147840,4759424,23797120,100509824,
               502549120,
%T A151019 2152467968,10762339840,46606146560,233030732800,1018160390144,5090801950720,
               22407240077312,
%U A151019 112036200386560,496198838730752,2480994193653760,11046580426440704,55232902132203520
%N A151019 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), 
               (-1, 0, 0), (1, 1, 0), (1, 1, 1)}
%H A151019 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 A151019 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, -1 + j, -1 + k, -1 + n] + aux[-1 
               + i, -1 + j, k, -1 + n] + aux[1 + i, j, 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 A151019 Sequence in context: A084154 A083099 A032095 this_sequence A004028 A080668 
               A062453
%Y A151019 Adjacent sequences: A151016 A151017 A151018 this_sequence A151020 A151021 
               A151022
%K A151019 nonn,walk
%O A151019 0,2
%A A151019 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008