# A114778 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 6 4 24 5 240 6 4320 7 120960 8 9676800 9 1567641600 10 438939648000 11 386266890240000 12 750902834626560000 13 2733286318040678400000 14 33674087438261157888000000 15 981936389699695364014080000000