84557168640domain: NAppears in sequencesOne eighth of octo-factorial numbers.at n=7A034976a(n) = 2^n * (n + 3)!!.at n=13A155160Number of permutations of [n] avoiding ascents from odd to even numbers.at n=15A231601a(n) = (n-1)! * n^n.at n=7A369569