# A152873 (b-file synthesized from sequence entry) 2 2 3 6 4 12 5 48 6 144 7 720 8 2880 9 17280 10 86400 11 604800 12 3628800 13 29030400 14 203212800 15 1828915200 16 14631321600 17 146313216000 18 1316818944000 19 14485008384000 20 144850083840000 21 1738201006080000 22 19120211066880000 23 248562743869440000 24 2982752926433280000 25 41758540970065920000