Number of lattice paths from (0,0) to (n,n) which do not go above the diagonal x=y using steps (1,k), (k,1) with k>=0.
A218321
Number of lattice paths from (0,0) to (n,n) which do not go above the diagonal x=y using steps (1,k), (k,1) with k>=0.
Terms
- a(0) =1a(1) =2a(2) =8a(3) =39a(4) =212a(5) =1230a(6) =7458a(7) =46689a(8) =299463a(9) =1957723a(10) =12996879a(11) =87383754a(12) =593794311a(13) =4071599216a(14) =28136612051a(15) =195756911831
External references
- oeis: A218321