# A119580 (b-file synthesized from sequence entry)
0 0
1 4
2 72
3 720
4 5600
5 37800
6 232848
7 1345344
8 7413120
9 39382200
10 203231600
11 1024287264
12 5062180032
13 24607819600
14 117942804000
15 558423072000
16 2615901857280
17 12139419556440
18 55866532906800
19 255192804636000
20 1157910842088000
21 5222177897816880
22 23422829664131040