# A330511 (b-file synthesized from sequence entry) 1 1 2 2 3 4 4 24 5 144 6 480 7 4320 8 40320 9 282240 10 4354560 11 36288000 12 319334400 13 6706022400 14 74724249600 15 1046139494400 16 20922789888000 17 376610217984000 18 4979623993344000 19 115242726703104000 20 2919482409811968000 21 29194824098119680000