528883domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(1)=2; thereafter, a(n) is the smallest prime not yet used which is compatible with the condition that a(n) is a quadratic residue modulo a(k) for the next n indices k = n+1, n+2, ..., 2n.at n=28A249782Prime numbersat n=43740