9408960000domain: NAppears in sequencesa(n) = n! a(n-1) / a(n-2), where a(0) = 1, a(1) = 1.at n=12A372993a(n) = n! a(n-1) / a(n-2), where a(0) = 1, a(1) = 2.at n=12A372994