# A203520 (b-file synthesized from sequence entry)
1 1
2 3
3 30
4 1680
5 900900
6 9535125600
7 4122929827336320
8 161481256755920962660800
9 1289130207153926967849156327590400
10 4850265693548396005370498087328884780717568000
11 20141097979706537636828034511787661382412368790843921121216000