Number 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, -1), (-1, -1, 0), (-1, 0, -1), (1, 0, 1), (1, 1, 0)}.

A150127

Number 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, -1), (-1, -1, 0), (-1, 0, -1), (1, 0, 1), (1, 1, 0)}.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =20a(4) =70a(5) =260a(6) =986a(7) =3852a(8) =15284a(9) =61646a(10) =251636a(11) =1038026a(12) =4320900a(13) =18123780a(14) =76544604a(15) =325197844a(16) =1389044326a(17) =5961411840a(18) =25695687106a(19) =111190743966a(20) =482866090476

External references