# A374497 (b-file synthesized from sequence entry) 0 1 1 6 2 36 3 200 4 1080 5 5712 6 29792 7 153792 8 787680 9 4009280 10 20304768 11 102405888 12 514678528 13 2579028480 14 12890311680 15 64283809792 16 319954540032 17 1589720712192 18 7886437652480 19 39069462835200 20 193307835764736 21 955361266917376 22 4716674314223616 23 23264437702656000