12015573923domain: NAppears in sequencesa(n) is the least x such that the n values x+0, x+6, x+12, ..., x+6*(n-1) are all products of exactly two primes (i.e., semiprimes).at n=15A091016a(n) is the least x such that the n values x+0, x+6, x+12, ..., x+6*(n-1) are all products of exactly two primes (i.e., semiprimes).at n=16A091016