Number of peaks of the form Ud 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).
A108427
Number of peaks of the form Ud 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) =1a(1) =9a(2) =85a(3) =833a(4) =8361a(5) =85305a(6) =880685a(7) =9173505a(8) =96220561a(9) =1014889769a(10) =10753517061a(11) =114375683009
External references
- oeis: A108427