42998951domain: NPropertiesPrimalityPrimeyesAppears in sequencesLeast prime divisor of T(n) which does not divide any T(k) with k < n, or 1 if such a primitive prime divisor of T(n) does not exist, where T(n) is the n-th central trinomial coefficient given by A002426.at n=18A242170Prime numbersat n=2604475