470597domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes of the form 2^r*7^s + 1.at n=15A077498Lower twin primes p1 such that p1-1 is a square.at n=21A145824Primes of the form 4n^3 + 1.at n=12A199307a(n) = 4*7^n+1.at n=6A199419Prime numbersat n=39276