n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 8 |
4 | 39 |
5 | 122 |
6 | 950 |
7 | 5042 |
8 | 45594 |
9 | 366243 |
10 | 3858148 |
11 | 39916802 |
12 | 494852628 |
13 | 6227020802 |
14 | 88543569808 |
15 | 1308012219556 |
16 | 21086562956045 |
17 | 355687428096002 |
18 | 6427672041650478 |
19 | 121645100408832002 |
[1,1,4,8,39,122,950,5042,45594,366243,3858148, 39916802,494852628,6227020802,88543569808, 1308012219556,21086562956045,355687428096002, 6427672041650478,121645100408832002] |