# A372988 (b-file synthesized from sequence entry) 0 1 1 1 2 12 3 120 4 140 5 252 6 4752 7 68640 8 109200 9 257040 10 6139584 11 109549440 12 210974400 13 591192000 14 16576876800 15 343108846080 16 758663942400 17 2419157664000 18 76585170816000 19 1777303822694400 20 4379008275532800 21 15472932418944000 22 540078624594432000 23 13756331587654656000