137203domain: NAppears in sequencesa(n) = floor((a(n-2)*a(n-1))/(a(n-1)+a(n-2))) + a(n-1) + a(n-2), a(0) = 0, a(1) = 1, a(2) = 1, ...at n=21A096080Number 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, 0, -1), (0, -1, 1), (1, -1, -1), (1, 1, 1)}.at n=10A149512