1.I want to know whether or not there are infinitely many primes p satistying gcd((p-1)/6,6)=1, such that 6 is a cubic residue mod p, but 2 and 3 are not cubic residues mod p? If there are, can we give a expression of p? 2. I have deduced that is p=1296k^2+36k+7 is a prime, then p satisfies the above conditions. Are there infinitely many such primes?