# A053014 (b-file synthesized from sequence entry) 1 1 2 30 3 60 4 840 5 10080 6 110880 7 1441440 8 15135120 9 21162960 10 21162960 11 232792560 12 26771144400 13 26771144400 14 2730656728800 15 30278164316400 16 33977306563200 17 38000934972000 18 3610088822340000 19 37400520199442400 20 390033996365613600 21 438120379479182400 22 4505020423775071200