484000domain: NAppears in sequencesNumber of discordant permutations.at n=18A000562E.g.f. sin(x*exp(x)).at n=10A009448Numbers with prime factorization p^2*q^3*r^5 where p, q, and r are distinct primes.at n=20A190470a(n) = Sum_{k=1..n} k * lcm(k,n).at n=39A344508