67369domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers whose least quadratic nonresidue (A020649) is 19.at n=28A025027a(n) is the largest minimal prime P such that, for any odd number b, the product P*b is a nonzero square modulo 8 and modulo each of the first n primes.at n=8A322269Prime numbersat n=6710