# A027160 (b-file synthesized from sequence entry) 2 5 3 21 4 176 5 680 6 5808 7 21840 8 190976 9 708480 10 6310400 11 23220736 12 209756160 13 767676416 14 7010676736 15 25558732800 16 235443322880 17 855858053120 18 7939647995904 19 28796047982592 20 268690773770240 21 972740537352192 22 9120760620646400