181721domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of distinct terms in row n of Stern's diatomic array, A049456.at n=27A293160Duplicate of A293160.at n=27A294443Odd integers k>=5 such that 2^((k-1)/2)-1 == 0 (mod k*(k-3)/2).at n=13A337848Prime numbersat n=16467