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, 0), (-1, 1), (0, 1), (1, -1), (1, 0)}.
A151451
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, 0), (-1, 1), (0, 1), (1, -1), (1, 0)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =9a(4) =29a(5) =107a(6) =395a(7) =1555a(8) =6225a(9) =25605a(10) =107267a(11) =456195a(12) =1967467a(13) =8577059a(14) =37771451a(15) =167734281a(16) =750539481a(17) =3380693983a(18) =15318535101a(19) =69782167449a(20) =319415226689
External references
- oeis: A151451