Number of 2n-step walks on cubic lattice starting at (0,0,0), ending at (n,y,z), remaining in the first (nonnegative) octant and using steps (0,0,1), (0,1,0), (1,0,0), (-1,1,1), (1,-1,1), and (1,1,-1).

A328427

Number of 2n-step walks on cubic lattice starting at (0,0,0), ending at (n,y,z), remaining in the first (nonnegative) octant and using steps (0,0,1), (0,1,0), (1,0,0), (-1,1,1), (1,-1,1), and (1,1,-1).