# A068550 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 3 4 12 5 10 6 30 7 105 8 56 9 252 10 1260 11 330 12 1980 13 2574 14 2002 15 15015 16 240240 17 61880 18 15912 19 151164 20 38760 21 406980 22 4476780 23 1144066 24 13728792 25 24515700 26 6249100 27 84362850 28 21474180 29 5462730 30 81940950 31 1270084725 32 645122400