1 1
  2 1
  3 2
  4 12
  5 12
  6 720
  7 720
  8 160030080000
  9 160030080000
 10 160030080000
 11 160030080000
 12 19363639680000
 13 19363639680000
 14 106124746688553188944907919360000000000
 15 964690192126173597722951161927432273920000000000000
 16 964690192126173597722951161927432273920000000000000
 17 964690192126173597722951161927432273920000000000000
 18 285296790950252850081548788581988650426683769697075200000000000000
 19 285296790950252850081548788581988650426683769697075200000000000000
 20 455255378681311856194606543374575948989928986708476393686466845083198814417735825885100084786364416000000000000000000000