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, 0, 0), (0, -1, 1), (0, 1, 1), (1, 0, -1)}.
A148791
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, 0, 0), (0, -1, 1), (0, 1, 1), (1, 0, -1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =8a(4) =25a(5) =77a(6) =257a(7) =865a(8) =3021a(9) =10549a(10) =37753a(11) =135438a(12) =494280a(13) =1806200a(14) =6678951a(15) =24716159a(16) =92336889a(17) =345207465a(18) =1299979995a(19) =4897841100a(20) =18561069686a(21) =70366144206a(22) =268059657293
External references
- oeis: A148791