157902domain: 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), (0, 0, 1), (0, 1, -1), (1, -1, 0), (1, 0, 1)}.at n=9A150489a(n) = Sum_{k=0..floor(n/2)} binomial(n-2*k,floor(k/3)).at n=53A376695