# A173469 (b-file synthesized from sequence entry)
2 1
3 2
4 5
5 16
6 62
7 280
8 1440
9 8296
10 52864
11 368848
12 2794864
13 22842048
14 200201408
15 1872466944
16 18608903968
17 195778297664
18 2173272774016
19 25380361760000
20 311011886153856
21 3989579297299712
22 53458990592638976
23 746817531317769728