n | a(n) |
---|---|
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 |
[1,6,30,135,600,2640,11610,51000,224040,984060, 4322400,18985440,83390760,366280800,1608831840, 7066542960,31038691200,136332618240,598819808160, 2630222793600,11552844224640,50744069991360] |