# A034094 (b-file synthesized from sequence entry) 1 1 2 20 3 312 4 9744 5 29280 6 53352 7 1666224 8 5006880 9 106798080 10 133301760 11 980733600 12 9099742080 13 18262471680 14 22794600960 15 1556055895680 16 3577201689600 17 4464942451200 18 380428773854896765462278360268800000