# A165213 (b-file synthesized from sequence entry)
0 1
1 6
2 30
3 150
4 750
5 3750
6 18750
7 93750
8 468750
9 2343735
10 11718600
11 58592640
12 292961400
13 1464798000
14 7323945000
15 36619500000
16 183096375000
17 915476250000
18 4577353125210
19 22886625003000
20 114432421904040
21 572158593987000