n | a(n) |
---|---|
0 | 1 |
1 | 9 |
2 | 66 |
3 | 434 |
4 | 2661 |
5 | 15525 |
6 | 87240 |
7 | 475920 |
8 | 2534400 |
9 | 13227520 |
10 | 67866624 |
11 | 343105536 |
12 | 1712390144 |
13 | 8449622016 |
14 | 41273524224 |
15 | 199782039552 |
16 | 959119884288 |
17 | 4570314964992 |
18 | 21629992173568 |
19 | 101729521631232 |
20 | 475697692803072 |
[1,9,66,434,2661,15525,87240,475920,2534400, 13227520,67866624,343105536,1712390144,8449622016, 41273524224,199782039552,959119884288, 4570314964992,21629992173568,101729521631232, 475697692803072] |