212370domain: 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, -1, 0), (-1, 1, 0), (0, 1, -1), (1, 0, 1), (1, 1, -1)}.at n=10A149432a(n) = Sum_{k=0..n} binomial(k+2,2) * binomial(2*k,2*n-2*k).at n=10A382230