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), (0, -1), (0, 1), (1, -1), (1, 0), (1, 1)}.
A151488
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), (0, -1), (0, 1), (1, -1), (1, 0), (1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =13a(4) =51a(5) =207a(6) =887a(7) =3907a(8) =17689a(9) =81598a(10) =382809a(11) =1819544a(12) =8748842a(13) =42469534a(14) =207900762a(15) =1025103628a(16) =5087012042a(17) =25386558037a(18) =127331796354a(19) =641546957748
External references
- oeis: A151488