6730949domain: NPropertiesPrimalityPrimeyesAppears in sequencesLeast prime divisor of Fr(n) which does not divide any Fr(k) with k < n, or 1 if such a primitive prime divisor of Fr(n) does not exist, where Fr(n) denotes the n-th Franel number given by A000172.at n=23A242169Prime numbersat n=459490