# A056385 (b-file synthesized from sequence entry) 1 6 2 30 3 120 4 720 5 2010 6 23820 7 46950 8 434700 9 1683450 10 15126810 11 36284466 12 547180200 13 1088416050 14 13060942950 15 58782162480 16 352913410080 17 1057916846190 18 16926687985950 19 33853322280030