# A355998 (b-file synthesized from sequence entry) 4 1 5 48 6 1728 7 62720 8 2457600 9 105815808 10 5017600000 11 261227298816 12 14860167413760 13 918839084134400 14 61439672177393700 15 4421589120000000000 16 340976534987475000000 17 28064307240230900000000 18 2456376885785930000000000