# A307617 (b-file synthesized from sequence entry) 1 1 2 2 3 4 4 6 5 12 6 60 7 120 8 360 9 840 10 2520 11 27720 12 55440 13 360360 14 720720 15 12252240 16 232792560 17 1163962800 18 3491888400 19 5354228880