348513domain: NAppears in sequencesNumber of primes less than n*10^6.at n=4A038815a = a(n) is such that the a-th prime p(a) is the least prime with digital sum equal to n, or a(n)=0 if no such prime exists.at n=57A104290Number of even semiprimes < 10^n. Number of terms of A100484 < 10^n.at n=7A220262