489231domain: NAppears in sequencesa(0)=1; thereafter, a(m+1) = Sum_{k=0..m} k!*a(m-k).at n=10A051295Number 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, 0), (0, 1, 1), (1, 0, -1), (1, 0, 0)}.at n=10A150242