n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 26 |
3 | 240 |
4 | 2904 |
5 | 43680 |
6 | 786960 |
7 | 16531200 |
8 | 396789120 |
9 | 10713669120 |
10 | 321413702400 |
11 | 10606692096000 |
12 | 381841394457600 |
13 | 14891820610867200 |
14 | 625456552834713600 |
15 | 28145546185236480000 |
16 | 1350986237814140928000 |
17 | 68900298484208615424000 |
18 | 3720616124549638938624000 |
[1,4,26,240,2904,43680,786960,16531200,396789120, 10713669120,321413702400,10606692096000, 381841394457600,14891820610867200, 625456552834713600,28145546185236480000, 1350986237814140928000,68900298484208615424000, 3720616124549638938624000] |