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), (0, 1), (1, -1), (1, 0)}.
A151430
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), (0, 1), (1, -1), (1, 0)}.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =7a(4) =19a(5) =61a(6) =224a(7) =771a(8) =2855a(9) =11005a(10) =41963a(11) =165661a(12) =664443a(13) =2674101a(14) =10955892a(15) =45281419a(16) =188288455a(17) =790957165a(18) =3343062477a(19) =14209485769a(20) =60792612875a(21) =261330644741
External references
- oeis: A151430