# A331724 (b-file synthesized from sequence entry) 1 1 2 6 3 672 4 30240 5 32760 6 23569920 7 45532800 8 14182439040 9 51001180160 10 153003540480 11 403031236608 12 518666803200 13 13661860101120 14 740344994887680 15 796928461056000 16 212517062615531520 17 87934476737668055040 18 154345556085770649600 19 170206605192656148480