Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 1)}.
A151490
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, -1), (1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =18a(4) =88a(5) =420a(6) =2205a(7) =11725a(8) =64974a(9) =365610a(10) =2104536a(11) =12269796a(12) =72582840a(13) =433722432a(14) =2618401071a(15) =15934054422a(16) =97711687502a(17) =603038843550
External references
- oeis: A151490