# A124903 (b-file synthesized from sequence entry) 5 2 6 12 7 30 8 240 9 720 10 60480 11 60480 12 7983360 13 1108800 14 518918400 15 21794572800 16 62270208000 17 87178291200 18 35568742809600 19 2 20 40548366802944000 21 304112751022080000 22 851515702861824000 23 2534272925184000 24 5170403347776995328000 25 51704033477769953280000