# A162743 (b-file synthesized from sequence entry)
0 1
1 6
2 30
3 135
4 600
5 2640
6 11610
7 51000
8 224040
9 984060
10 4322400
11 18985440
12 83390760
13 366280800
14 1608831840
15 7066542960
16 31038691200
17 136332618240
18 598819808160
19 2630222793600
20 11552844224640
21 50744069991360