163716domain: NAppears in sequencesC(2n-1,n-1) mod n^4.at n=21A099908Numbers k such that Bernoulli number B_{k} has denominator 3404310.at n=29A295596a(n) = binomial(2*c-1, c-1) (mod c^4), where c is the n-th composite number.at n=12A298946