244016domain: NAppears in sequencesNumber of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (-1, 1, 0), (0, -1, 1), (1, 0, -1), (1, 0, 0)}.at n=11A148719a(n) = Sum_{k=0..n} binomial(k+2,2) * binomial(k,3*n-3*k).at n=15A392313