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, 0)}.
A151489
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, 0)}.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =14a(4) =57a(5) =255a(6) =1186a(7) =5799a(8) =29214a(9) =151276a(10) =800575a(11) =4315567a(12) =23632575a(13) =131179116a(14) =736815104a(15) =4181873345a(16) =23954877894a(17) =138356539814a(18) =805056779656
External references
- oeis: A151489