n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 2 |
5 | 10 |
6 | 40 |
7 | 141 |
8 | 464 |
9 | 1480 |
10 | 4600 |
11 | 14145 |
12 | 43052 |
13 | 130480 |
14 | 393820 |
15 | 1186521 |
16 | 3568784 |
17 | 10725760 |
18 | 32213200 |
19 | 96714465 |
20 | 290284052 |
21 | 871142800 |
22 | 2613981700 |
23 | 7843080201 |
24 | 23531425304 |
25 | 70598731840 |
26 | 211804847800 |
27 | 635432109585 |
28 | 1906330676252 |
29 | 5719061512720 |
30 | 17157321139180 |
[0,0,0,2,10,40,141,464,1480,4600,14145,43052, 130480,393820,1186521,3568784,10725760,32213200, 96714465,290284052,871142800,2613981700, 7843080201,23531425304,70598731840,211804847800, 635432109585,1906330676252,5719061512720, 17157321139180] |