# A203155 (b-file synthesized from sequence entry)
1 1
2 6
3 33
4 168
5 984
6 5640
7 37440
8 246240
9 1853280
10 13880160
11 117391680
12 989936640
13 9315855360
14 87500528640
15 907925760000
16 9408462336000
17 106785133056000
18 1210848984576000
19 14928525545472000
20 183922359312384000
21 2448351304261632000