# A145681 (b-file synthesized from sequence entry) 1 2 2 20 3 24 4 360 5 816 6 1056 7 12240 8 15840 9 29120 10 181632 11 2724480 12 9192960 13 13790400 14 15288000 15 93358848 16 199180800 17 1130734080 18 1400382720 19 25115166720 20 544161945600 21 3089165506560 22 11519246340096 23 172788695101440 24 274358081249280 25 5944425093734400 26 33746043993661440 27 7425442423511040000 28 25976914334122752000000 29 48787315395486187520000 30 56897897650906642513920