Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, 0), (1, 1)}.
A151373
Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (-1, 1), (0, -1), (0, 1), (1, 0), (1, 1)}.
Terms
- a(0) =1a(1) =0a(2) =3a(3) =5a(4) =30a(5) =111a(6) =548a(7) =2586a(8) =13087a(9) =67422a(10) =356949a(11) =1926267a(12) =10572832a(13) =58881097a(14) =332036571a(15) =1893134282a(16) =10898885385a(17) =63289478066a(18) =370367463568
External references
- oeis: A151373