981976

Appears in sequences

• Number of lattice paths from (0,0) to (n,0) that do not go below the x-axis and consist of steps U=(1,1), D=(1,-1) and H=(1,0), where H-steps are only allowed if y=1.at n=21A224747
• Number of equivalence classes of ballot paths of length n for the string ddu.at n=39A274112