n | a(n) |
---|---|
0 | 1 |
1 | 8 |
2 | 20 |
3 | 1 |
4 | 1680 |
5 | 1 |
6 | 90720 |
7 | 1 |
8 | 4435200 |
9 | 1 |
10 | 207567360 |
11 | 1 |
12 | 6538371840000 |
13 | 1 |
14 | 423437414400 |
15 | 1 |
16 | 67580611338240000 |
17 | 1 |
18 | 35763659520196608000 |
19 | 1 |
20 | 6155242080686899200000 |
21 | 1 |
22 | 117509166994931712000000 |
23 | 1 |
[1,8,20,1,1680,1,90720,1,4435200,1,207567360,1, 6538371840000,1,423437414400,1,67580611338240000, 1,35763659520196608000,1,6155242080686899200000,1, 117509166994931712000000,1] |