# A364771 (b-file synthesized from sequence entry) 1 1 2 720 3 51840 4 737280 5 9360000 6 37324800 7 276595200 8 754974720 9 3061100160 10 6739200000 11 25721308800 12 38220595200 13 137037962880 14 199148544000 15 485222400000 16 773094113280 17 2008994088960 18 2203992115200 19 6114035779200 20 6900940800000 21 14338695168000 22 18519342336000 23 41348052472320