n | a(n) |
---|---|
0 | 1 |
1 | 20 |
2 | 220 |
3 | 1760 |
4 | 11440 |
5 | 64064 |
6 | 320320 |
7 | 1464320 |
8 | 6223360 |
9 | 24893440 |
10 | 94595072 |
11 | 343982080 |
12 | 1203937280 |
13 | 4074864640 |
14 | 13388840960 |
15 | 42844291072 |
16 | 133888409600 |
17 | 409541017600 |
18 | 1228623052800 |
19 | 3621204787200 |
20 | 10501493882880 |
21 | 30004268236800 |
[1,20,220,1760,11440,64064,320320,1464320,6223360, 24893440,94595072,343982080,1203937280,4074864640, 13388840960,42844291072,133888409600,409541017600, 1228623052800,3621204787200,10501493882880, 30004268236800] |