# A138896 (b-file synthesized from sequence entry)
2 3
3 15
4 280
5 11340
6 798336
7 86486400
8 13343616000
9 2778808032000
10 750895681536000
11 255454710858547200
12 106826515449937920000
13 53858368206010368000000
14 32215590089995124736000000
15 22555515290152300904448000000
16 18272974787062050706056806400000
17 16959604724241965811558973440000000