# A232980 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 2
4 8
5 40
6 40
7 280
8 2240
9 2240
10 22400
11 246400
12 246400
13 3203200
14 44844800
15 44844800
16 717516800
17 12197785600
18 12197785600
19 231757926400
20 4635158528000
21 4635158528000
22 101973487616000
23 2345390215168000
24 2345390215168000
25 58634755379200000
26 1524503639859200000
27 1524503639859200000