104580domain: NAppears in sequencesNumber of conics which pass through 3 points and are bitangent to a general curve of order n.at n=21A060783Numbers k such that k and k^3 are sums of two twin primes.at n=25A213811a(n) = (n+1)!! mod n!!.at n=13A227415a(n) = (2n)!! mod (2n-1)!! where k!! = A006882(k).at n=6A232618