# A024923 (b-file synthesized from sequence entry)
1 1
2 2
3 6
4 24
5 120
6 840
7 6720
8 60480
9 665280
10 8648640
11 138378240
12 2352430080
13 44696171520
14 1028011944960
15 25700298624000
16 693908062848000
17 20123333822592000
18 623823348500352000
19 19962347152011264000
20 738606844624416768000
21 30282880629601087488000
22 1302163867072846761984000