n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 9 |
3 | 20 |
4 | 489 |
5 | 998 |
6 | 4481 |
7 | 9960 |
8 | 243521 |
9 | 497002 |
10 | 2231529 |
11 | 4960060 |
12 | 121272969 |
13 | 247505998 |
14 | 1111296961 |
15 | 2470099920 |
16 | 60393695041 |
17 | 123257490002 |
18 | 553423655049 |
19 | 1230104800100 |
20 | 30075938857449 |
21 | 61381982514998 |
22 | 275603868917441 |
23 | 612589720349880 |
24 | 14977757157314561 |
[1,2,9,20,489,998,4481,9960,243521,497002,2231529, 4960060,121272969,247505998,1111296961,2470099920, 60393695041,123257490002,553423655049, 1230104800100,30075938857449,61381982514998, 275603868917441,612589720349880,14977757157314561] |