n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 9 |
4 | 80 |
5 | 660 |
6 | 6714 |
7 | 77084 |
8 | 1005640 |
9 | 14572944 |
10 | 233086920 |
11 | 4066783512 |
12 | 76906345944 |
13 | 1566049091568 |
14 | 34153725715368 |
15 | 793996577407560 |
16 | 19595885746343808 |
17 | 511550462381982528 |
18 | 14080034085212120256 |
19 | 407434430977558009344 |
20 | 12363449947108075756800 |
[1,1,2,9,80,660,6714,77084,1005640,14572944, 233086920,4066783512,76906345944,1566049091568, 34153725715368,793996577407560,19595885746343808, 511550462381982528,14080034085212120256, 407434430977558009344,12363449947108075756800] |