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, 1)}.
A151459
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, 1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =9a(4) =31a(5) =110a(6) =417a(7) =1610a(8) =6443a(9) =26109a(10) =108187a(11) =452431a(12) =1920684a(13) =8211507a(14) =35485309a(15) =154206122a(16) =675502094a(17) =2972505787a(18) =13161176353a(19) =58492256069a(20) =261228659937
External references
- oeis: A151459