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, 1), (0, -1), (0, 1), (1, 0), (1, 1)}.
A151479
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, 1), (0, -1), (0, 1), (1, 0), (1, 1)}.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =17a(4) =77a(5) =345a(6) =1649a(7) =8081a(8) =40603a(9) =207911a(10) =1080842a(11) =5691069a(12) =30285103a(13) =162630700a(14) =880180326a(15) =4796131934a(16) =26290963023a(17) =144882598329a(18) =802180091860
External references
- oeis: A151479