n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 3 |
4 | 18 |
5 | 90 |
6 | 480 |
7 | 3360 |
8 | 27720 |
9 | 249480 |
10 | 2479680 |
11 | 27276480 |
12 | 327650400 |
13 | 4259455200 |
14 | 59623724160 |
15 | 894355862400 |
16 | 14309953257600 |
17 | 243269205379200 |
18 | 4378836875212800 |
19 | 83197900629043200 |
20 | 1663958347802150400 |
21 | 34943125303845158400 |
22 | 768748742605299456000 |
[1,1,1,3,18,90,480,3360,27720,249480,2479680, 27276480,327650400,4259455200,59623724160, 894355862400,14309953257600,243269205379200, 4378836875212800,83197900629043200, 1663958347802150400,34943125303845158400, 768748742605299456000] |