n | a(n) |
---|---|
0 | 1 |
1 | 3 |
2 | 9 |
3 | 31 |
4 | 126 |
5 | 606 |
6 | 3428 |
7 | 22572 |
8 | 170856 |
9 | 1467432 |
10 | 14123808 |
11 | 150644448 |
12 | 1763377344 |
13 | 22466496960 |
14 | 309371685120 |
15 | 4577183527680 |
16 | 72390548206080 |
17 | 1218507923427840 |
18 | 21746087150745600 |
19 | 410094720409651200 |
[1,3,9,31,126,606,3428,22572,170856,1467432, 14123808,150644448,1763377344,22466496960, 309371685120,4577183527680,72390548206080, 1218507923427840,21746087150745600, 410094720409651200] |