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, 0, 1), (0, 0, -1), (0, 0, 1), (1, 1, -1)}.
A148729
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, 0, 1), (0, 0, -1), (0, 0, 1), (1, 1, -1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =7a(4) =25a(5) =73a(6) =281a(7) =925a(8) =3715a(9) =13163a(10) =54363a(11) =202455a(12) =852991a(13) =3292995a(14) =14084535a(15) =55873491a(16) =241813049a(17) =979932617a(18) =4281582977a(19) =17650788629a(20) =77729583213a(21) =324985250073
External references
- oeis: A148729