n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 0 |
3 | 1 |
4 | 4 |
5 | 10 |
6 | 24 |
7 | 67 |
8 | 200 |
9 | 586 |
10 | 1704 |
11 | 5049 |
12 | 15232 |
13 | 46284 |
14 | 141240 |
15 | 433696 |
16 | 1340500 |
17 | 4164830 |
18 | 12993792 |
19 | 40697472 |
20 | 127941300 |
21 | 403561902 |
22 | 1276763096 |
23 | 4050430502 |
24 | 12882398456 |
25 | 41068966204 |
26 | 131211997496 |
27 | 420056152498 |
28 | 1347272602056 |
29 | 4328764460928 |
30 | 13931034024536 |
[1,0,0,1,4,10,24,67,200,586,1704,5049,15232,46284, 141240,433696,1340500,4164830,12993792,40697472, 127941300,403561902,1276763096,4050430502, 12882398456,41068966204,131211997496,420056152498, 1347272602056,4328764460928,13931034024536] |