84513domain: NAppears in sequencesNumbers of the form m = p1 * p2 * p3 * p4 where for each d|m we have (d+m/d)/2 prime and p1 < p2 < p3 < p4 each prime.at n=12A128285Integers n such that 6n, 36n, and 216n fall between pairs of twin primes, that is, 6n-1, 6n+1, 36n-1, 36n+1, 216n-1, and 216n+1 are prime.at n=22A192851