Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of 2 n steps taken from {(-1, 0), (-1, 1), (1, -1), (1, 1)}.
A151402
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of 2 n steps taken from {(-1, 0), (-1, 1), (1, -1), (1, 1)}.
Terms
- a(0) =1a(1) =2a(2) =16a(3) =140a(4) =1484a(5) =16980a(6) =205928a(7) =2602288a(8) =33905132a(9) =452379572a(10) =6151336384a(11) =84946062728
External references
- oeis: A151402