%I A149846
%S A149846 1,2,4,12,38,118,424,1544,5668,22186,86962,347260,1426428,5869950,24589692,
               104252754,444133962,
%T A149846 1916625390,8318626668,36335194794,159998657938,707382646426,3146397539508,
               14064764511358,
%U A149846 63107673236226,284521869849658,1287188819030996,5843899644335638,26625968697335426
%N A149846 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, 0), (1, 0, 0), (1, 1, -1)}
%H A149846 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 A149846 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, j, k, -1 + n] + aux[i, -1 + 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 A149846 Sequence in context: A148212 A149844 A149845 this_sequence A108532 A000940 
               A008404
%Y A149846 Adjacent sequences: A149843 A149844 A149845 this_sequence A149847 A149848 
               A149849
%K A149846 nonn,walk
%O A149846 0,2
%A A149846 Manuel Kauers (manuel(AT)kauers.de), Nov 18 2008