n | a(n) |
---|---|
1 | 2 |
2 | 4 |
3 | 20 |
4 | 168 |
5 | 2016 |
6 | 31680 |
7 | 617760 |
8 | 14414400 |
9 | 392071680 |
10 | 12189864960 |
11 | 426645273600 |
12 | 16606346803200 |
13 | 711700577280000 |
14 | 33307587016704000 |
15 | 1690360041097728000 |
16 | 92472637542405120000 |
17 | 5425061402487767040000 |
18 | 339780161524233830400000 |
19 | 22629358757513973104640000 |
[2,4,20,168,2016,31680,617760,14414400,392071680, 12189864960,426645273600,16606346803200, 711700577280000,33307587016704000, 1690360041097728000,92472637542405120000, 5425061402487767040000,339780161524233830400000, 22629358757513973104640000] |