203936639domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of nondecreasing Dyck paths of semilength n and having no peaks at even level (n>=0). A nondecreasing Dyck path is a Dyck path for which the sequence of the altitudes of the valleys is nondecreasing.at n=28A121485Prime numbersat n=11284834