73265596607domain: NAppears in sequencesNumber 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).at n=11A108448Expansion of (1 + x)^11 / (1 - x)^12.at n=23A240876