# A307663 (b-file synthesized from sequence entry)
1 1
2 6
3 41
4 329
5 3090
6 33654
7 420792
8 5981688
9 95782320
10 1712555280
11 33909364800
12 737868052800
13 17521164259200
14 451126883894400
15 12522623670144000
16 372847351488998400
17 11853064556660275200
18 400718191717647820800
19 14354714544806716416000
20 543129329390299739136000
21 21642934280974058207232000