# A227461 (b-file synthesized from sequence entry)
1 1
2 2
3 12
4 128
5 1920
6 37104
7 877184
8 24520320
9 791112960
10 28932902400
11 1182789053952
12 53447706998784
13 2645389044480000
14 142326283714836480
15 8270318699325112320
16 516187815998727389184
17 34440412737701955502080
18 2446191865021002009477120
19 184278436717136012676956160