492059domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) = prime((a(n-1)+1)/2), a(1) = 9.at n=13A104296Smallest member of Sophie Germain pair, where each member of the prime pair is the smallest of its prime triple (p, p+2, p+8).at n=7A237188Prime numbersat n=40927