86199238125domain: NAppears in sequencesa(n) = (2n-1)!!/lcm{1,3,5,...,2n-1}.at n=22A025549a(n) = (2n-1)!!/lcm{1,3,5,...,2n-1}.at n=23A025549Product of first n odd nonprimes, a(n) = Product_{k=1..n} A071904(k).at n=8A306848