550476domain: NAppears in sequencesa(n) = Sum_{k=0..2n-3} T(n,k) * T(n,k+3), with T given by A027023.at n=5A027049Number 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, 1), (1, -1, 1), (1, 0, 1), (1, 1, -1)}.at n=10A149487