n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 3 |
4 | 18 |
5 | 120 |
6 | 1170 |
7 | 12600 |
8 | 176400 |
9 | 2608200 |
10 | 46607400 |
11 | 883159200 |
12 | 19429502400 |
13 | 447567120000 |
14 | 11629447830000 |
15 | 316028116404000 |
16 | 9516436753824000 |
17 | 297478346845680000 |
18 | 10151626256147376000 |
19 | 359237701318479984000 |
20 | 13733349319337487840000 |
21 | 542212802070902202240000 |
[1,1,3,18,120,1170,12600,176400,2608200,46607400, 883159200,19429502400,447567120000,11629447830000, 316028116404000,9516436753824000, 297478346845680000,10151626256147376000, 359237701318479984000,13733349319337487840000, 542212802070902202240000] |