Number of d steps in all paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1), U=(1,2), or d=(1,-1).
A108430
Number of d steps in all paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1), U=(1,2), or d=(1,-1).
Terms
- a(0) =3a(1) =31a(2) =311a(3) =3151a(4) =32299a(5) =334335a(6) =3488239a(7) =36627487a(8) =386618387a(9) =4098713631a(10) =43611791783a(11) =465496885231
External references
- oeis: A108430