272385447domain: NAppears in sequencesNumber of length n left factors of Dyck paths having no UUDD's; here U=(1,1) and D=(1,-1).at n=35A191794The number of peaks of width 1 (i.e., UHD configurations, where U = (0,1), H=(1,0), D=(0,-1)) in all bargraphs of semiperimeter n (n>=2).at n=18A273716