n | a(n) |
---|---|
2 | 1 |
3 | 5 |
4 | 20 |
5 | 124 |
6 | 744 |
7 | 5928 |
8 | 47424 |
9 | 426816 |
10 | 4268160 |
11 | 50578560 |
12 | 606942720 |
13 | 8369256960 |
14 | 117169597440 |
15 | 1757543961600 |
16 | 28120703385600 |
17 | 498974747443200 |
18 | 8981545453977600 |
19 | 177051737331302400 |
20 | 3541034746626048000 |
[1,5,20,124,744,5928,47424,426816,4268160, 50578560,606942720,8369256960,117169597440, 1757543961600,28120703385600,498974747443200, 8981545453977600,177051737331302400, 3541034746626048000] |