# A052662 (b-file synthesized from sequence entry) 0 1 1 2 2 8 3 54 4 480 5 5400 6 72720 7 1144080 8 20563200 9 415860480 10 9344160000 11 230958604800 12 6227499801600 13 181909958630400 14 5722470212659200 15 192874123233792000 16 6934147333521408000 17 264875092391669760000