n | a(n) |
---|---|
0 | 1 |
1 | 3 |
2 | 14 |
3 | 54 |
4 | 306 |
5 | 918 |
6 | 4524 |
7 | 25560 |
8 | 168828 |
9 | 1315764 |
10 | 11998584 |
11 | 125358192 |
12 | 1466062200 |
13 | 18835528104 |
14 | 262376016912 |
15 | 3927709053792 |
16 | 62795044663056 |
17 | 1067217284481840 |
18 | 19208039592749472 |
19 | 364940846656681536 |
20 | 7298740111856220576 |
21 | 153273039685710932448 |
22 | 3372003538678423189440 |
[1,3,14,54,306,918,4524,25560,168828,1315764, 11998584,125358192,1466062200,18835528104, 262376016912,3927709053792,62795044663056, 1067217284481840,19208039592749472, 364940846656681536,7298740111856220576, 153273039685710932448,3372003538678423189440] |