n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 5 |
3 | 17 |
4 | 74 |
5 | 394 |
6 | 2484 |
7 | 18108 |
8 | 149904 |
9 | 1389456 |
10 | 14257440 |
11 | 160460640 |
12 | 1965444480 |
13 | 26029779840 |
14 | 370643938560 |
15 | 5646837369600 |
16 | 91657072281600 |
17 | 1579093018675200 |
18 | 28779361764249600 |
19 | 553210247226470400 |
20 | 11185850044938240000 |
21 | 237335752951879680000 |
[1,2,5,17,74,394,2484,18108,149904,1389456, 14257440,160460640,1965444480,26029779840, 370643938560,5646837369600,91657072281600, 1579093018675200,28779361764249600, 553210247226470400,11185850044938240000, 237335752951879680000] |