# A034620 (b-file synthesized from sequence entry)
0 1
1 0
2 540
3 21120
4 286740
5 2132352
6 10878300
7 44012160
8 146719620
9 417436800
10 1093070376
11 2572283520
12 5570541780
13 11568510720
14 22583167200
15 41422741632
16 75113550180
17 129368897280
18 214148621340