51933domain: NAppears in sequencesa(1) = 1, a(n) is the smallest integer > a(n-1) such that the largest element in the simple continued fraction for S(n) = 1/a(1) + 1/a(2) + ... + 1/a(n) equals n^4.at n=4A070904Numbers k such that 33*10^k + 1 is prime.at n=28A271107