Number of walks of length n on square lattice, starting at origin, staying on points with x >= 0, y <= x.

A060900

Number of walks of length n on square lattice, starting at origin, staying on points with x >= 0, y <= x.

Terms

    a(0) =1a(1) =2a(2) =7a(3) =21a(4) =78a(5) =260a(6) =988a(7) =3458a(8) =13300a(9) =47880a(10) =185535a(11) =680295a(12) =2649570a(13) =9841260a(14) =38470380a(15) =144263925a(16) =565514586a(17) =2136388436a(18) =8392954570a(19) =31893227366a(20) =125515281892a(21) =479240167224

External references